Speaking to the lens shift (or lack thereof) on the 3020, that's the one thing I did *not* like about it. In fact, I came very, very close to not buying the unit for this reason alone. I use a 120" screen that comes down to about 18" off of the floor, and thus the top of the screen is roughly 6.5 feet above the floor, or 3.5 feet down from my 10-foot ceiling. I really liked that my old projector could be one foot from the ceiling--well out of range of the random "bump". With the 3020 and my setup, the lens center has to be an inch below the top of the screen. If not, the projector has to be angled down, making the image wider at the bottom and narrower at the top. Same with side-to-side. If it's not perfectly centered, you'll has one side being wider on one edge than the other. Careful measurement avoids this side-to-side problem, but it does stink having to hang your projector down so far from the ceiling if you have a semi-high ceiling. And, of course, with lens shift you can make minute adjustments to center everything perfectly without skewing the image. Thus--I think lens shift is an important feature, and I feel it ought to be on all projectors even though you set it and forget it. Just like focusing... set it and forget it.
As for keystone correction, if I understand how it works correctly, it essentially deletes portions of pixels thus "compressing" the image on the top or bottom to take the skew out of it. Although I've heard some projectors do it better than others, I've never seen one where it wasn't noticeable. Some look absolutely horrendous even with minor correction. IMHO, they ought to outlaw keystone correction...!!!!! I'd much rather have a 3.5' ceiling mount than use keystone correction (but... lens shift would have been very nice!!!)
With that said... I have seen some reviews of this projector mentioning the 3020 "defocusing" when the unit heats up. They recommended waiting for the unit to heat up and THEN focus it. That way, although the unit will be out of focus for 5 mins or so after being turned on, it will come into focus thereafter. I haven's had a problem with this at all (nor was it difficult to focus, although the focus slider is sensitive). Has anyone had a problem with the unit changing focus as it heats up? I just wonder if it's a bug they fixed.