You get a bit of speed if you set Frameskiping to 1, Framelimit off. Enable EFB copy to texture, Lighning Melee and NO ITEMS. The items reduce a bit the speed.
Just installed XP 64 next to Windows 7 32-bit and tested out DolphinIL.
There was quite a noticeable improvement; I can get 60 fps in single player playing Mario Kart: DD and Super Smash Bros Melee looks and feels faster too, but it's still lagging in character heavy areas.
Should I go ahead and give my video chipset an upgrade at this point?