Well, I had three reboots with this latest firmware.  Once about two days after upgrading, then again a day later, then a day after that.  Each time was under moderate wireless load, watching a SD video from my HTPC across a network link.  The stream would slow down, stutter in fits and spurts for a minute or so, then the router would reboot.
I installed my Netgear WNDR3700 yesterday and it's a breath of fresh air.