Well, I made the same choice a while ago.
I don't care about 3D at all, and went for the $1000 price difference. Despite some of the stories regarding the 8700UB I got a refurb from Projector People.
I'm projecting on a 110" screen and couldn't be happier. There is a chance you may get a bad unit and need to exchange it (possibly more than once) but Epson
is really outstanding in that 2 year warranty period. MY unit was pretty much perfect out of the box.
I fully realize that this technology is still evolving, so for me it was a place holder until we see affordable LED or Laser based 1080p units.
Given that criteria, the 8700ub is a wonderful unit. It is PLENTY bright, I have to run it in eco mode at night and there's plenty left in standard mode for some TV watching
in a non-blacked out room.
The 5010 may be a better projector on paper, but if you want to save some money and don't need 3D, the 8700UB does a fine job at a substantial cost saving.
Want 3D? That's a no brainer. The 5010.
Welcome to the darkside.....