My preference is the Sennheiser. I have 2 lav's sets but I can mix channels on my camera, you may need to get one of those Beachtec (or other) type boxes so you can mix before the camera. I'm very happy with the Sennheiser and twice, in 5 years, was at an event where another professional had the same. In one event we just used one mic and transmitter on the podium and set our receivers to the same frequently, I got my conference audio and he got his speaker audio. In the other event I'd already mic'd a speaker when a news videographer buzzed in and out using my audio.
