I've been using the Powerbar 2 at home at least twice a week for the last few months and it works just as advertised (I must have done a couple of thousand reps by now easy so I think I've used it enough to have a valid opinion).
Worth noting :
1. The bar folds flat so it can stored easily. 2. The bar coped with my 13 stone weight (I'm more like 12 stone now). 3. I have performed ballistic pullups but the bar tends to shift a little when used like this so it might not be appropriate for clap pullups and the like. 4. There has been some minor damage to the paint work but it's very minor and way higher than my eye line so not noticeable.
For anyone interested, I use the bar to perform two main types of pullup : full hang to full contraction (standard overhand grip pullup) with a 3 second count up, 3 second count hold at top, 3 second down and 3 second hang - rinse and repeat). I found these very tough when I started but now this speed is pretty easy (I'll do 3 sets of 8 - 15 reps). The second type is just a full hang to full contraction as fast as I can, so more of a power routine. The bar easily copes with these. Lastly, I'll do hanging leg raises (legs at full extension) for an great core workout - I'd recommend these to most people though beginners may need to reduce the range of movement and consider hanging knee raises before full leg raises.
Oh and one last tip, If you start suffering from Golfer's Elbow (pain in the inside of your elbow), consider using some form of wrap / grip device for half your reps. Also remember not to flair your elbows out too much - don't point them in, just don't let them flair out from your body - these two things stopped my Golfer's Elbow dead in its tracks. Good luck!