Used one for a little while and liked it a lot - certainly powerful enough for general use, and competed well with my 580EX II (prior to my switch over to Nikon)
My one gripe with the Yongnuo units in general are that the heads do not really lock into place very solidly - if I try to use my speedlight beauty dish, the flash head pivot is more or less useless as it can't counteract the weight of the modifier.
Just received mine today. Am very impressed withe the build quality and performance, as far as I've had chance to test it. In particular, I was very pleased with the way it functioned in multi mode: I fired about 20 continuous shots with successful flash every time. ETTL seems to be working fine.
Jon: in case you're interested, I bought mine from this seller on eBay. Bought it Sunday the15th and it arrived this morning, the 18th. (And it's a fiver cheaper today. Poop.)
No idea about the remote power up, sorry, I'm a very basic flash user! But there's quite a detailed review here which may have the info you want : review
