I tried to use beta17 and had major problems; every time someone placed an order it would spew debug messages (mostly the same one over and over) until the log file reached 2 GB, sometimes in a matter of minutes! Rather impressive if you ask me. :) The SSL connection actually worked fine, but that wasn't much consolation.
I had to go back to nsd3.3 rather quickly and haven't had a chance to try the latest from CVS, but I've been told on the AOLserver list that the problem I had should be fixed.