Beta 6 doesn't like me. Downloaded but didn't do anything, ie just showed standard Beta 5 selection screen. Exited and looked for update exe; was none. Ran Beta 5 again and it said do you want to continue your download, yes, then began to install as normal. (Maybe my ISP decided to take a nap at an inopportune time.)
CraterMA online A1 test conditions frame rate: 125 (i.e. same as Beta 5).
At first I got a bunch of artifacts like grey boxes or windows in the sky, thousands of tiny flashing grey boxes on the ground in fields surrounding ports, flickering every 6 seconds, but after restarting a few times they went away. (Maybe my graphics card is going south for the winter.)
Several times I was unable to exit, screen just stays there but mouse acts like it's accessing underlying desktop. Had to reboot or use task manager to kill.
On my system, in a tank, while zoomed into the now dense forests of CraterMA tank town my frame rate falls to as low as 6.
E8400 @ 3GHz, 8GB RAM, 2GB HD7870, XP 32bit, 1920x1080, 4K textures, stnd FOV.