what is it that you want to do with XBMC? just stream movies using addons? or play local content of storage (USB flash drive, hardrive...)
ezeecube is a one man team, mainly a Developer. His box ezeecube is his first shot at hardware. It supposed to be good for easier photo sharing or something. put basically your taking a BIG gamble with ezeecube. Seems like you will not even use his added software and your paying a big premium for less hardware and support. so forget about ezeecube.
Pivos is a multi-millionare company already made a previous box and has support and basically it ill work but the hardware isn't as good as firetv. but both will be fast.
ezeecube isn't even a real product as of this moment and its not even worthy to be compared to Pivos. so Pivos if its between them to.
Firetv is I think $10 cheaper than Pivos. You do understand that XBMC is an open source software and is not a consumer product so its best to learn little things like installing addons and all that. seriously its not that hard to get xbmc up and running. here is a video (one of many) instructing you to install. you can't tell me you can't follow simple instructions?
http://www.youtube.com/watch?v=F5ucKpV4rac
you would get allot more fun and enjoyment out of XBMC if you learn how to use it. So installing xbmc on firetv wont be the hardest thing you do once you have XBMC up and running so you can do it. buy the firetv
Amazon rep