The Epson 3020 does not have lens shift. That's reserved for the 5020 and the 8350/8700 models from them.
The big difference between the HD33 (I assume you meant) and the Epson is that the Optoma is a DLP model and the Epson is a LCD. Both are very good at what they do, but the Optoma is known to have a bit less lag time. I like the look of DLP a bit more, but the rainbow effect does hit me sometimes and I've stuck with LCD displays over the years and have been happy with them.
Realistically, they are both quality displays and both capable of delivering a good 2D and 3D image for an entry level 1080p 3D projector.
You SHOULD look at your placement flexibility options in your room to see which one works best for you and you should read the reviews of the projectors at the various websites. Besides here, you should look at ProjectorReviews.com and ProjectorCentral.com which both do some good reviews of projectors.
Really, in my opinion, it's a toss up on these. They both are good, neither is great, neither is seriously lacking in any specific area that the other excels in.