Got an HL72A650. Thought I'd share my thoughts with all of you:
1) WOW! The PQ is amazing. I didn't know if there would be any change in PQ as the TV got to this size vs the 50A650 I already have.
2) The cabinet on the 72 is definitely sturdier than the 50A650. You can still bend it a bit, but not as easily as the 50.
3) I got one with nearly perfect geometry.
4) I haven't had it long yet, but I have not run into any issues with it. I have all sources connected to a Denon 3808 and then to the TV over HDMI. I will see if there is a difference in the upscaler of the TV vs the receiver and try to post it back here if I get a chance.
5) Great Price for a Great TV! If you live in NJ, you can go to Electronics Expo and ask them to match their website price (currently $2019.88), they guy also matched the lowest price I could find on the mack warranty combo, and their low website price on a Harmony 880. They will have to bring the TV from their warehouse. I ordered mine on Sunday, it was in store on Wednesday. The price had dropped $90, and they price adjusted for me.
6) Viewing angle is really good. I have this in a basement, and off to the side of the viewing area is a workout area. I can see the image beautifully from my treadmill, so vertical and horizontal viewing angles are good.
I highly recommend this TV if you want BIG. Sitting 8-10' away seems to be optimal, at least to me. This thing is huge (but I still wish they had an 80!). I looked at the Mitsubishis vs the Sammy, and I didn't see a significant difference in PQ, plus you can't beat the price.