Using the nightly build from today (3a85677) i am unable to use VESA modes and ReactOS falls back to VGA mode.
GPU: HD 6870
CPU: Intel Core 2 Quad Q6600
MBO: Asus P5N-E SLI
Not really related, but installing the Radeon drivers works, but it causes as Assert to fail, j < 32. I am not currently able to provide logs, but i will be able to in a few hours.