Game isn't all too bad...it's almost exactly the same feel as Unreal Tournament. The vehicles can, and probably will, require a lot of tweaking...Strogg vehicle mechanics are abhorrent.
Graphically, on my "underpar" system of a vanilla 6600 256mb and 3.0GHz P4 with 1GB of RAM, it runs decently at the levels it automatically detects for me, the only change I made internally was turning down the obnoxiously loud music and the Ani-Filter...I'm not all too worried about 'pretties' as I am enjoyment.
Currently, in it's beta form, it's fairly good...could use some minor touch-ups here and there graphically for usability purposes.
All-in-all, the game plays remarkably well...albeit like any beta test there are pitfalls...such as the disconnects, lag, and the occasional crash (which I just had).