AFAIK, you can access BBC catch-up but not sure you’ll have “full” iPlayer i.e. what you can get on a desktop, but rather whatever BBC makes available to Sky on catch up.
Box-sets, yeah, there are tons of them.
WiFi hook-up is good – means you download catch-up stuff via web rather than a signal, and can start watching it after 1 or 2% has downloaded. There is the option to download SD or HD versions.
Search function is excellent – brings up a list of all programmes related to the search, when they’re showing (so if eg. you want to series link a show, you can see when it’s being shown at say, the middle of the night and record from there.
There’s a good kids section (for those who allow their kids to watch kids tv – I’m not one of those, no way sir. 😀 ).