I did also make the leap during holidays and changed to the CSSU thumb. The upgrade went without hitch. I'm still amazed how much snappier the N900 feels now! I'm now kicking myself that why I didn't do this much earlier... It feels like the N900 did get a RAM upgrade to 512MB.

With little tweaks in CSSU transitions times the experience is further improved.

In my opinion the CSSU should at some point drop the conventional (ARM) compiled branch and only continue with the thumb2 branch. Is there a reason why anyone would need to stay with the ARM branch? (Unless they want to stay with stock kernel, for which I don't see a reason either...)