I use an older one day-to-day and used one of the new ones only briefly. however, in using the new one, i don't feel like I really missed anything (screen size). In fact, I think it's bigger depthwise, but that just might be perception.
One improvement i will note in the new one is the banishment of the three feet that somewhat plague the first ASD 17".
while designed to slip an iMac keyboard underneath, they lose flexibility since any platform for the monitor has to be as wide/deep as the three feet. now, with the solid plastic base, you can get away with a smaller footprint.
For me, that's important since my heigh adjustable monitor platform isn't all that deep