Any good?
get an Intel Mac Mini instead
Why?
Can you pipe iPlayer straight into your telly proper good style?
Just buy a LCD TV with a VGA input and connect it to any old PC / laptop - works fine and much more flexible than the Apple TV box.
They got a lot better since xbmc was ported to them - gives you the best of both worlds, all the apple-centric stuff when you want it and xbmc for anything it wouldn't normally play.
Or else pick up a classic xbox and they're easily modified to run xbmc too.
Apple TV - very nice. You can do similar things with PS3 and XBox, but the interface and experience is nowhere near as neat.
If it wasn't for cartoon network and the pause & record functions I'd get rid of V+ and stick with AppleTV.
If it's iPlayer you want then any old PC will get you that. Although there I'd be inclined to stick with the V+ service as that has iPlayer available as well as lots of other on demand stuff.