In my experience, and after owning several wireless units (never had the AKG "bug", but had the Samson one) the Sennheiser EW172 G2 is the best I've ever used by far in every aspest, shy of slight advantage in convenience of a bug. They are a bit pricey, but IMO you definitely get what you pay for!
The unit is all steel and is rack-mountable, has tons of channels to choose from, can auto tune to lock into the best channel based on where you are (I use this feature at every venue we play just to minimize possible interference). You can adjust squelch, input signal, output signal, you can mute the transmitter, the signal self mutes if you unplug the unit while on, etc., etc., etc. The transmitter is what was called a "fanny pack" design, but it can easily be mounted via the stainless stell clip to a strap, or, as I do, put it in my left pocket, and route the cord through my belt loops around to the input. Between sets I just unplug, and keep the plug in my right pocket until it's needed again. Simplicity.
I think it's unfair to compare the 2 units. The Sennheiser is more of a pro unit, while the AKG is a beginners intro to wireless, so to speak.
Good luck with whatever you choose!
