I have heard of issues with provisioning that can delay porting, but for the most part we don't have issues with porting. Not sure how it works with a Sero plan, though, we don't use those.
I port numbers all the time for my end users - from Nextel (which is funny), Cingular, T-Mobile, and VZW.
I agree, though, that the night crew can be a little lackluster.
No longer a BES Admin, but it was fun while it lasted!