I've just installed the Roku and it seems to have a lot more apps than nowtv, probably because it's not tied into the SKY model which nowtv is. Also has an embedded netflix one which is a key thing I wanted. Tells me I've got 30 days for using plex and then a one off fee (think it's about £5 but I may install rarflix, will see how used to it I get.

I'll have more of a play over the next week or so.