I've just spent a few minutes looking at the Wiki, readme and other
things online, and don't find anything that sounds like a must-have
patch for c32491sp4 - are there any consider must-have?

I've been running a late beta of SP3 with generally good results, but
once in a while people are losing connection to their mapped drives on
the server, so I thought I might give a newer c32 a try.