I've joined the revolution -
Any good ??
Not really.
Depends how you look at it. If it's as a way of wirelessly streaming content from your iOS device(s) then I'd say it's very good. But I'd agree that it is stripped of functionality that should be included.
As you say, it would be a much better device given some extra functions. A basic web browser would be good and the lack of Flash (sigh!) hamstrings the youtube bit so severely that it's not worth using. As others have stated, too, the movie rentals are rather expensive which encourages you to buy them instead. I'd rather do that on disc so that I can watch them anywhere. All this turns my rash purchase into a small black paperweight and as I now have the old version it's probably worthless on the second hand market, as we all know how the Apple fanboi likes his latest and greatest version. 
Why do people insist on bringing up the flash issue?
It is a defunct technology that is being taken over by HTML5 which iOS devices support. Most major websites including YouTube are already converting there content. Why also would you need a basic web browser? It's not what it's designed for. My TV and PS3 have web browsers. But I don't use them. I use my iPad or Mac for that.
Yes it has limitations compared to some other devices out there, some of which cost less. But for something that just works out of the box, gives the ability to stream music, videos and pictures to your TV from a Mac, iPad or iPhone and access to a growing catalogue of VOD from a variety of vendors (granted the price of some is high) Then I think it's a very good piece of technology.
Why people seem to compare its functions to a PC/Laptop is beyond me. But Haters be hating
