What are ALL the differences between the 2?

There are no hardware differences other than the extra memory.

Philips constantly changes the actual components they use. Over time there have been quite a few different screens used. It seems they have now settled on the one screen which is about the same as the orignal 1000 screen.

This doesn't answer your question but your question isn't really answerable. It really depends on exactly when it was built.

I am ready to order a TSU2000 and would like to know if the contrast issue has been resolved. I know there is a large thread on this issue that started mid last year, but it wasn't perfectly clear if the contrast problem is a closed issue.

There is no answer to your question, except to say it is absolutely "luck of the draw"!

The screen issue has no other answer; some are just "different" than others. ALL screens are much poorer than the average Palm PDA for example.

Sorry--talk to Phillips if you want no help!

All TSU2000 models come with exactly the same screen, which is (in my opinion) about 95% as good as the screen on my original TS-1000. The "luck of the draw" thing happened with mid-to-late US & European 1mb models.

My TSU2000 screen is not as nice as the older TS-1000 screens I have seen in the past. Less definition, edges not as defined etc. I continue to be disappointed by the touch sensitivity of the screen. Some have suggested using the back of my fingernail but this is difficult and akward. I am disappointed in the ergonomics and user interface. The programming model is excellent but I am going to reutrn the unit as I am tired of having to press the same LCD button 2-3 times for it to recognize my command. Too bad, I like the concept of Pronto. Smith from Newport Beach

I'm not exactly what they mean by "back" of the fingernail, but I find the "tip" works good and doesn't require a big change of your finger's regular position.