DFS – questions on Samba/SMB/CIFS

My environment is an array of Mac Pro’s and Mac Mini’s, all on Leopard. I’m waiting until 10.6.3 for Snow Leopard as it always takes a bit to get everything worked out. We used to talk to a Windows 2000 server that had SFM installed. Unfortunately, it crashed, and we moved them to another Windows 2000 Server, this time using SMB out of the box. Performance dropped off slightly. Now we moved that infrastructure into Microsoft’s DFS, with the backend being an array of NAS storage, accessible by CIFS/SMB. Per the recommendations, I tried out ExtremeZ-IP; that was a mistake. Not to mention the widget or the client worked terribly, the product on the server wasn’t stable enough. I’ve been doing this for 8 years so I have a good idea of what’s good and what’s not. And that wasn’t. Not to mention, all it does it make my users connect to another server just as a pass-through out to the NAS. So we’re going with Admit-Mac; I don’t mind the product as it’s got a nice auto mount feature and it’s connects using DFS. But there’s still some performance issues that I keep seeing and that, through network traces, etc, looks to be a lot of chatter via SMB. Doing the research, Leopard has an older build of Samba installed and I don’t really want to go through compiling the latest Samba and making a mess of my users’ machines. Is there a DMG packaged install of the latest Samba? Or is there another way to get my Mac users to talk to the DFS shares via AFP? The performance connecting over CIFS isn't the best and after making all the recommended changes to the smb.conf file, it's still leaving something to desire.