I've long used Sennheiser wireless "bodypack" systems; they're widely thought of as "the shizz" in the professional audio business, and with good reason.  They just work and are beasts -- rugged, no-BS, locking microphone and output connectors, etc.

The age is showing on my kit, however, and Sennheiser just released a new setup they call the "Profile 2."  It comes with two transmitters with pseudo-omni (facing front only) capsules in them -- and each also has a locking TRS connector for an external lav or similar mic, a 2-channel receiver (outputs either mono or stereo, so you can have two separate channels or both transmitters into mono), will output not just through a standard TRS cable but also through either USB-C or Apple's Lightning connector (both connectors included) and the entire kit is tiny.  Each transmitter also has something like 30 hours worth of audio memory (16Gb!) (so you can literally use it as a detached micro-recorder!) and it can be put in a mode where it will send and back up to the memory at the same time.  The transmitters are both light and tiny -- roughly 2" x 1" x 3/4" including a spring body clip w/1/4" threaded hole on the bottom and the actual capsule.  Included are two very strong magnets on the storage bar (which might work ok on a dress shirt, but not a flannel or other thicker fabric) and the clip on the body pack is ferrous metal so that's the "mating" surface for them.  For size reference if you're familiar with the older Sennheiser body packs four of these transmitters consume basically the same space as one of the older type -- and these new ones do not have an external antenna sticking out of them either.  The transmitters have two buttons on them -- a power button (hold on/off) and a red "internal" record enable/disable (short press) and mute (long press) button.  There are three small LEDs along one corner -- power on (green), link confirmed (green = ok, red = out of range or jammed) and recording (red = yes, otherwise off.)

The receiver is also tiny and has a cold-shoe clip-on to go onto a camera or similar if you want to mount it that way, along with a standard 1/4" thread. Status (battery level on the transmitters that are powered on) and levels display on that screen there.  The receiver can be set for either mono blended output (into both channels) or stereo (each mic as a separate channel.)  Settings are accessed from the receiver; it has an OLED screen that is touch-sensitive.  Being very small the touch sensitivity can be a bit finicky -- don't expect to use it "live" without the risk of hitting the wrong thing, but for setup it works perfectly well.  There is no app integration at all (e.g. bluetooth) as with some other (much more expensive) modern systems but it outputs either over USB or a traditional mini TRS stereo plug (non-locking.)  The receiver also, in a nice touch, has a separate mini TRS headphone/monitor output with individual volume control accessed via the menus.

The entire setup runs on 2.4Ghz band so there are no licensing issues with transmission being digital.

Construction is engineered plastics with the batteries being internal and non-replaceable.  There is a battery in each module and one in the docking bar which charges the other units when they're inserted.  Exactly how many times it can charge the units assuming  the docking station is full is not claimed.  All connections on the units are the more-modern USB-C (yay) which I applaud loudly as USB-C is a lot more robust and less-likely to be damaged than the older "mini" connector.  With the units docked plugging in the base charges everything whenever the modules are inserted and the power button on the side allows it "all" to be turned on as a rather interesting if somewhat-odd "stick mic" you could use like a conventional microphone with both plugged-in transmitters active -- and yes, there's a 1/4" screw mount on the bottom of the bar so you really could stick it on a mic stand.

The whole kit fits in a supplied zippered case for transport or storage.

The best part is that the entire system is reasonably-priced.  Not cheap, but reasonable.  Then again, this isn't "Joe's Chinese Garbage" so..... yeah.

I grabbed one from B&H.

I like it.  A lot.  With one caveat that might kill it for you, and you should be aware of.

Many lavs which are otherwise compatible with this setup (basically anything that has a TRS connector and uses bias current from the pack will work with it, including previous Sennheiser lavs) are not shielded at the capsule.  The cable is shielded but the bias circuitry in the capsule is not and thus it can (and in some cases does) pick up interference from the transmitter signal (the receiver is also transmitting sync/seek and status info) so if the capsule its in the "wrong" place related to either you can hear it as a quite-audible and high-frequency, raspy, but low-level "buzz."  Both of my prior-generation Sennheiser lavs do this and after investigation I discovered its not the wire that is unshielded, its the capsule itself on the end of the wire.  If you set the body units to "record" and turn off the receiver (thus disabling the transmitter side) it goes away so if used as a "recorder" it doesn't exhibit the problem -- but when used as a transmitter it does.  Clearly something in the microphone capsule is rectifying and down-converting some element of the RF signal from the body pack into the audible range -- and that's a bitch as its in the external lav mic itself and thus is almost-certainly a function of the frequency band the units are running on and happenstance as to the harmonics generated when it is rectified by said circuitry.

Thus you will have to very carefully test the lavs you have, if you intend to use external ones, with the system while its still in the return window and figure out if you'll run into this problem or not.  From reading around the 'net this is extremely common with other 2.4Ghz systems too -- including DJI's (in other words, not just the cheap ones) which have the same issue.

I don't know if Sennheiser can correct this in a future revision of the hardware -- or if their newer lavs are better-filtered at the capsule end.  Mine are quite-old but there's utterly nothing wrong with them and they were not cheap either, nor are Sennheiser's current ones so I have no intention of buying new ones to find out.  This is definitely a dropped ball situation for Sennheiser, which was quite unexpected (really guys, you didn't think people who bought this would own some of your excellent lavs in different patterns already and work this through before releasing this thing -- or note the problem if you couldn't fix it in the user manual?)

For my particular uses of this kit I'm not sure I care since "ultimate concealability" isn't a material part of the use case for me, and thus clipping the entire transmitter unit on my lapel or in a vest pocket works fine -- and as I noted, the internal capsules are typical Sennheiser quality (in other words, excellent) and they come with snap-on windscreens as well  (which you will want for outdoor use; indoors they're not needed if at lapel or vest-pocket level as plosives are not typically a factor with a mic placed there.)

Thus my qualified recommendation -- good, but with the qualification that either you don't need external lav capability or the ones you have (or buy for external use) don't exhibit the problem with interference.

Updated note: The extremely reasonably-priced "Neewer" (a Chinese knock-off company) LAVs are appropriately-shielded and while they lack the locking collar (thus take care how you route the wire lest the potential for it to be pulled out while in-use exists) and aren't Sennheiser level quality they work perfectly well with this kit -- I detect zero interference in my testing.  The capsules are quite-small under that huge windscreen (which just pulls off) if you're indoors and thus don't need it and.... they're cheap.