I have a request to you all.
You will find two binaries attached to this post. One with UAE m68k emulation and second with Cyclone emulation.
Could you test your favorite apps/games using both binaries? Does it run, the performance, is it cycle accurate etc.

Just copy both files to your N900 to /home/user, uncompress (gzip -d uae4all-*.gz), add execute rights (chmod +x uae4all-*)
and run the binary.

Alex, could you check whether the -cyclone binary fixes your speed problems (with not overclocked N900) and your frameskip Auto issues?

I still haven't decided which core is better for N900.

Cyclone should be faster but it could be less compatible. You may notice that it is significantly smaller.