The AE3000's Lens Memory Feature
Leaving aside frame interpolation, the one other major feature that might cause you to opt for the Panasonic AE3000 over the Sanyo Z3000 is its Lens Memory. However, this is only relevant if you are interested in setting up a 2.35:1 super wide Cinemascope screen instead of the standard 16:9 screen. If you aren't, you can skip this section.
As discussed in the AE3000 review, Lens Memory lets you automatically set the zoom lens to a wide angle setting to fill a 2.35 screen, so that you can view a 2.35 format film in full frame without any black bars. Then when you switch to a 16:9 source such as HDTV or a 1.78 film, you can press a button, and the projector will automatically zoom the lens to a position where the 16:9 image fills your screen vertically. And, unless the projector is positioned exactly at a height equal to the middle of the screen, a vertical compensation adjustment is required to get the image to center vertically on the screen. The AE3000 automatically makes this adjustment as well. Essentially, this eliminates the expense of a separate anamorphic lens.
You can accomplish the same thing on the Z3000, but the zoom lens is manual. So for each change of material between 2.35 films and regular 16:9 material, you must manually adjust the lens to accommodate it. And, if necessary, you must then manually adjust the vertical height of the image as well. This can be a tedious procedure if you do it very often.
So in a nutshell, the situation is this: if you don't want to install a 2.35 format screen, the AE3000's Lens Memory is an irrelevant feature for you. If you want to install a 2.35 screen and want also to use an anamorphic lens, you can use it on either the AE3000 or the Z3000, so again the Lens Memory feature is irrelevant. However, if you want to get into 2.35 format and don't want to spend $4,000 to $7,000 on an anamorphic lens, the AE3000 gives you a very practical and easy to use alternative.