I like Gargoyle firmware, which is based on OpenWrt. It has a simpler interface with QoS ready to go. The experimental version 1.5.9 has CoDel built in. So far the router seems to be handling VoIP better than the Asus RT-N16 running Shibby's TomatoUSB firmware.
I'm using an Optimus V on VM as well, but my experience with their "unlimited" data is disappointing. I have been using the service since May, 2011, and the bandwidth typically doesn't serve more than 40 KB/s consistently around my area. For instance, listening to a stream via TuneIn is unbearable, because VM data service can't even stream at 32 K without buffering every few seconds. It doesn't matter that VM advertises unlimited data or have a 2.5 GB fast cap when the service can't even be used besides reading email.
If I were a new user, I'd go with T-Mobile instead of Virgin Mobile. T-Mobile uses GSM so switching to a new phone won't require calling up VM for activation -- just pop in the SIMM card. Right now there's no way to use a newer CDMA phone without losing my grandfathered $25/mon plan.
https://www.gargoyle-router.com