Play a warrior here, I love your 6.50 UI. Huge life bar, including an extra orb bar. I can see all my stats, HP, and target in one window so I'm not constantly shifting around. And everything is nice and BIG. I especially liked the extra horizontal inventory window that I stretched across the top of my screen.
The 6.50 plus didn't do it for me though... The pet window mixed with the inventory makes it bulky and the target/HP player window didn't have all the info like in the previous one. Though, I can see how this might be better for pet classes.
Still a nice one, and I still use your 6.50 version.