Thank you for this fast replies!
It looks like I just made this deceision on a pretty perfect timing, just read about 5.6.1 yesterday.
So basically, if I'd update up to 5.4.4.2, I had to reinstall screensaver hack and backdoor lock, thats not so bad. But I guess, I'll simply stick with 5.4.3.2 until there would be some crucial features added (and a jailbreak availiable
)