Just got my SL-6000 last night (from Amazon).
I keep quite a few notes on my Zaurus (was SL-5500), and have been using the Pocketop IR keyboard for about a year.
I am happy to report that IRK 10.0 works just fine on the SL-6000. Just make sure that you put it in "SL5600/SLC7xx" mode.
I also found that Zeditor works great on the SL-6000. I had been using it fine on the SL-5500 as well.
The SL-6000 is a nice machine, but I definitely feel like Dirty Harry ("This is the most power PDA made") walking around with it in my pocket. Although it isn't that much bigger than the SL-5500, it feels big when one is used to the petite 5500.