I think it is definitely a step up from the Optoma in it's setup versatility and that the lumens listed are much closer to calibrated lumen output instead of listing a 'max' lumen output like so many other manufacturers. A little honesty goes a long way in my belief of a reputable product.
The projector itself isn't nearly as versatile in setup as a Z4 or AE900, but it offers lens shift on DLP which, at that price, is a big perk if you need it.
But, if you don't need the lens shift, and your theater is dark, and your screen size is about 100" so you don't need the extra brightness, then I would think that the HD72 would be fine.
So, it is, once again, an 'IT DEPENDS' answer. Plus, if you have the chance to see the AE900 or Z4 those are two units that may make you very happy for a few years until 1080p becomes more prevalent in the marketplace. I personally am recommending those units for people who are pretty sure they will want 1080p front projection a few years down the road.