Been reading this thread with interest. I have been using a tachyon xc now each day for about 8 months. Was going to buy a bunch of new batteries again which would set me back nearly 30 quid. Decided to go buy a muvi because you can recharge it, also the tachyon is pretty useless at night. Seen many vids with night time footage and was impressed. I have posted a few vids of my tachyon on youtube and so might do a comparison. Got the muvi from scan yesterday for £54. Impressed so far, took it out in the car last night and again in good street lighting it's very good. Waiting for my sports pack to arrive so that i can try and attach it to my helmet. Also waiting for the waterproof cover to come out. My Tachyon is totally waterproof so hope the cover is out soon. Also just bought the MD80 version off
ebay for £13.50 thought it was worth the gamble to have a backup or another camera for a reverse shot. Will let you know how it goes and post some new footage with the muvi. Look for sallysaile on youtube if your interested in seeing what the Tachyon is like.