First, these are just the settings I have. Some of them may or may not even matter for performance. It's just where I ended up by messing around.
My starting point nearly a year ago was this BB FAQ, plus another that I can't seem to find: Linksys Router Tips - BlackBerryFAQ
I'll post pics, but since those go away over time, here's where the settings are.
For the Actiontec, go to the Advanced tab, the on the left is the QOS link. In the traffic priority screen, you can add new priorities. Under All Devices I have the Linksys, my desktop, and my VOIP box set to priority 6. Under wireless I have the Curve set to 6 as well.
Why everything at priority 6? No reason, pick whatever you want. I tried different priorities and the desktop would stutter on file downloads. So I bumped it to 6 and no degradation in call quality that I can tell.
I just literally noticed that there's an Input Rules and Output Rules section. I thought it was all the same stuff, so I was only really prioritizing Input. I've added the same things to Output as well, which might actually enable me to use this router instead of the Linksys full time.
On the Linksys, under the NAT/QOS tab I have the MAC Priority for the Curve set to Premium. This is dd-wrt v .24. Others are similar as far as I remember.
Also on the Linksys, under the Wireless>Advanced Settings tab are the settings where the BB FAQ comes into play. One big thing is to Enable the WMM Support. That's something I got from another FAQ. It prioritizes VOIP, streaming video, etc.
Some folks increase the TX Power as well. My place is small so I just stick with the default. Also you can see I ignored the Fragmentation Threshold and RTS Threshold figures from the FAQ. Those seemed to make things worse way back, but I updated them after I took the screen shot. Just to see if it makes any difference.