video card, so it is actually RR that makes the "lag". I use a M10k, and it is plenty fast for music/video/GPS/Phoco/SNES emulator. What you are refferring to is the lag from when you click "Music" on the main menu with the spinning logo to when the screen with music pops up. This "lag" should only happen once, because RR only loads the skin files as it goes. There is a setting in the roadrunner *.ini file I believe that you can change that will make RR take a bit longer to startup, but it loads all skins at the beginning eliminating that lag.
And as for the flash skins, the M10k is not fast enough if you are using the onboard video. But you have a GeForce card so that should be plenty fast. Are you sure that you installed your video drivers correctly if this setup you have is giving you slow times? Because default windows' drivers work to make video display but it is slow as all hell with nvidia cards. Make sure you download and install the latest nvidia signed drivers for your card because if you haven't, you will see a great difference in speed.
I suggest to check the drivers, and then download a flash intensive skin and try to run it. Even if you don't like the skin just try it to see the speed it goes with. I think you will be positively impressed with the speed. I forget the actual line in RR's ini file you need to change, but once i find it I'll post it. Change that too!
If it is not good enough then go the upgrade route. And maybe I'll buy your M10k if you put it up for sale! I love these little boards!
Well there is a dual core mini-itx board out there and it will work just fine. You might need to get DDR2 memory though because I don't think it takes DDR memory. They don't consume that much power even though it is quite a bit more than the epia boards. So you should be fine with your power supply. Just a 5 minute change out of parts if you need to upgrade.