So I'm on firmware 4.2.1 using MyWi and was looking at the 4.3.3 jailbreak. Nothing seems of interest to me besides the Personal Hotspot.
I'm with AT&T and have the old plan that is unlimited everything. I heard people were getting messages from AT&T about using tethering. I have not but don't use it much at this time.
My question is should i just stick with MyWi 4.0? Is there any reason to go to 4.3.3 and use personal hotspot?
Not in my opinion, no. 4.3.3 is not much different than 4.2.1. With all the work involved to update/upgrade, I would wait until 5.0 or 5.1 is released, get something really new, and the bugs have been worked out.