I did Flash 1.5 on my 64MB Cybook... It didn't start up fast at all, more than 1 minute waiting with the 3 dots screen... In folder view[*], going up from a subfolder to the main folder (where I have one subfolder for each author) was also a long wait... Let's see if it builds some caches or something and it's faster next time
[*] Yay! Folders!