I just moved, and between my work schedule, my unpacking/redecorating etc... I have had no time to actually experiment with the 1000. I DID play it for about a half hour ... enough to love the screen, the sounds, and the polish they added to the styles. It truly is a scaled down 4x.
Here's my take on the comparisons:
PA4x:
4 outputs (silent slab)
upgraded action
more sliders, physical controllers
solid, metal case
XLR mic in
4 harmony voices
upgraded MAXX EQ
PA1000:
**SPEAKERS** (very good ones)
slightly lighter action (almost identical to 900)
controllers, and sliders are on screen (not physical)
14" mic in
3 harmony voices
Very useable master EQ/Mastering (scaled down)
**extra USB slot (can be used for a light, if desired)
Sounds are very similar (to me)
Styles seem tweaked to be more 4Xish
My plan is to keep the 1000 at home and do my master recordings, and edits on it, and use the 900 on the job.
When things calm down, and my home studio is fully operational (like the death star), I may put more time into the 1000, but the main reason I bought it was for the screen. I sold my older 900, and now my newer 900 is an on-stage backup to the new, pristine studio unit. (PA1000)
In summary - I love it.