Keep jailbreak, or upgrade to 4.3.3?

I have an Apple iphone 3GS, a few pointer keep the jailbreak, or update in order to 4.3 OR MORE.3..if i update will probably my cell phone run more rapidly then it might on 5.2.1 previous to i arrest broke what’s more , it are presently there any small features that may be useful using a 3gs in 4.3 OR MORE.3 or could it be mainly a Ipad/ Iphone 3gs 4 bring up to date.

keep this on FOUR.2.A SINGLE.