Well, the N900 was the logical step after the N8XX. That is true internet in your pocket plus full phone functionality.

I have tried everything the OP posted except debian and windows and the dreaded CSSU. Why in gods name would I want openoffice and windows on this thing? In addition I have installed (wasted time) on numerous MeeGo derivates.

I say stock is just fine. Stock does everything just fine. Although overclocking can be fun (for a day or two) there is no real gain.