the new Beta was fast to install and didn't take a long time. The precaching also didn't last that long (on a small route) + loading a different route (Milwaukee Road Avery - Drexel) was not a huge deal either. However, SpeedTrees on this route don't render that far away and the FPS still drops...
I forgot to reply to your message, but again: I also would like to test the Beta version. Especially to test the performance + a rendering issues with random baseboards at the corner of the screen being either not rendered or with artifacts (I first discovered it earlier this year)