The 500 is great for FTA. There are some 3rd party apps and plug-ins that can be used to get netflix. And I think there is some type of IPTV plug-ins that will work with it as well. It will not do DVB-S2 or ASTC or MPEG4 or even HD but it truly is a great FTA STB.
the 7025 can decode mpeg2 720p HD (it outputs it as 480i)
the 800 and 8000 can tune dvb-s2 and decode 1080i/720p mpeg2/mpeg4 no ATSC though
there is a 500HD on the horizon as well, but not released yet, it wont do ATSC though either.
there are 800 clones out there, avoid them like the plague unless you get them for super cheap and just want something to play around with and your handy with your C++ and hexeditors