Very expensive, but I got to use my friends brand new Dyson DC41mk2 the other day. I normally can't stand Dyson's, but really like that one and it really lifted the carpet pile. Brushroll controls too, so you can go from carpet to hardfloor without having to get the hose out.
If it's just for corners, the DC58 is the same, but without the long tube and docking station. And £100 less.
If it's for proper vacuuming, though, aavoid them, because the charge only lasts 20 minutes and a tiny fraction of that if you use the boost - plus you have to keep the trigger pressed all the time you're using it.
I love my DC58 for places where it's difficult to reach with my DC24 and to save on quite so much lugging up and down the stairs, but couldn't have it as my main cleaner.
I just got a dc41. I have a normal dyson already. The battery one is very handy for around the kitchen, quick tidy up after meals as I have three messy small kids. It wouldnt replace my main one though, but I have been surprised at how good it is on carpet...shocking amount of dust picked up the first time! Shop around, there are lots of different prices.
I don't have a pet, only messy children, but I have a DC59 animal and I'm impressed on how well it picks up. I find it so much more convenient to grab and do a quick vacuum compared to having to having to get the corded cleaner out. I can do a quick clean of the whole house easily on one charge too.
The dust collection cylinder does need frequent emptying as it is very small but it's not too much effort to do.