First and foremost, three years in a row, no other projector near the price can match the Epson's "best in class" black level performance. There are a number of other "ultra-high contrast" projectors in this group, but the Epson's blacks are the blackest!
Black levels alone however, won't win a Best In Class award. This Epson gets the award despite only a modest improvement in blacks from the previous year. It's all the rest of the things the Epson does that also make it award worthy, that push the Epson to the top:
Brightness is much better than average. Actually the Home Cinema 8500UB with about 500 calibrated lumens in "best" mode is about average brightness for a "best" mode. Still, that's well below the brightest, yet a lot brighter than the dimmest. The thing is, when you need maximum lumens, then the Epson is one of the brightest projectors anywhere near its price. Only the BenQ W6000 musters up a noticeably brighter image when in "brightest" mode. (And the BenQ's color, at maximum brightness isn't as good as Epson's).
Brightness and black level performance isn't everything. Shadow detail of the Epson is only OK, it's definitely not one of the stronger performers when it comes to revealing dark shadow detail. That said, Epson more than makes up for that, with a very dynamic image with lots of "Pop and Wow" factor!
The Epson calibrates very well, and the final measurements are very good. Colors look really good, although the Epson is a touch less natural looking than some competition. As such, while it may be a favorite of many enthusiasts, it's possible that the true "purist" will look elsewhere.
Placement flexibility is about as good as it gets, with the longest range zoom lens, and lots of lens shift.
Warranty - the Epson comes with what has to be the best 2 year warranty in the business - if it fails under warranty (two years), Epson will ship out a replacement unit, next day, and pay all freight. While there are a few longer warranties only Epson's Pro series - with the same warranty but one extra year (of warranty, and replacement program), really can be considered a truly better warranty overall.
The Home Cinema 8500UB is pretty feature laden. That said, Epson keeps the mechanics simple with manual zoom, focus and lens shift, while a number of competitors have motorized some or all of those features. Getting beyond the placement flexibility, other strengths that weighed in our award decision process, included long term cost of operation (the 8500UB has a very low cost lamp ($299), and it lasts twice as long as most (rated 4000 hours at full power). The Epson definitely could be quieter, but it is by today's standards about average for home theater projectors. That's not to say a few aren't a lot quieter (a few are)!
Key dynamic features, in addition, of course, to the dynamic iris, include CFI (creative frame interpolation) for smoothing out fast moving objects, and pans. Their CFI is actually very good (though not the best). It is nicely improved over last year's 6500UB. In addition there's Super-Res, a dynamic sharpening tool that really does seem to give the 8500UB a feel of being a sharper projector. Just remember, dynamic features, while improving some things, often create minor artifacts in related areas, such as making faces appear a bit too contrasty. Using these dyanmic controls in moderation, however, works out very well.