EMates, in my view, do have distinct advantages: a physical keyboard and built-in localtalk are not to be sniffed at. The form factor also makes them better — much, much better — for actual use as note-taking devices (with 24+ hrs of battery life) in classroom contexts. They are generally better for running NewtonWorks than the others (e.g, the screen is more readable because slightly bigger, an eMate will sit on your lap, it has a very usable keyboard, etc.). And they are fast enough for any of the uses for which they were intended. Quite honestly for most of the things you would do with one, you would not find an eMate to be especially "slow."
But the 2000/2001 otherwise rule the roost in the Newton flock for speedy handwriting recognition, for use as an organizer, for modern connectivity hacks like Bluetooth, etc.
If you plan to try to push the machine into using current technologies like Bluetooth, get a 2100, not a 2000 — but don't expect it to be faster at doing any of that than an eMate is going to be when doing the things it was meant to do back in 1996-97.