Seeing as I'm the potential seller this may be biased but my two cents are valid as I've owned both of them.
QUOTE(utx @ Aug 6 2009, 04:34 PM)
Cons: Much worse keyboard (one row less, when pressin upper row, your fingers touch the top part edge).
This was a HUGE problem for me. It's actually been a turn off to me for most sliders in general. The Aigo and the Sony Mylo also suffered a little from this problem, but on the N810 it was terrible.
In terms of productivity, I could do just about anything on the Zaurus, but the N810 only got use if I wanted to check email.
Having large storage space available in the Zaurus is a great feature, even more so when you consider modding with a larger CF card in place of the microdrive. I have done this on a Z3200 and have a 16GB card there. The N810 has 2gb (I think?) internal storage, though expansion via mini sd (ugh) is possible.