As _LJB1 said in his review of the previous 0.4 version, there is a TON of potential with this layout. It's a strange layout. Maybe that's what I like about it? So many of the turns are double-apex like on Twin Ring Motegi. It changes the way you have to approach the turn and makes this layout standout on its own instead of being the same ole thing.
It is a shame that you aren't using 3dsmax or Blender because I think this has the potential to be really, really awesome layout. I think the track itself would need a teeny bit of tweaking, but even if the track surface all stayed the same...I could see myself running a lot of laps on here.
I won't repeat everything that _LJB1 said, but his thoughts are right on the money with mine. It needs atmosphere, but I guess Race Track Builder doesn't work that way. A shame...
1. yeah the pitlane is a massive work in progress still, will fix up the grass next update.
2. Haven't got around to doing a physics pass on the track yet, will do my best to include at least a physics barrier for the Armco in the next update.