OK, well this is embarrassing! I downloaded your track while I was in France, gave it a ride, then completely forgot to review it. I'll re-download and re-ride it shortly and give you some feedback. Thanks for bringing it up in Jer's thread, it'd have been completely forgotten otherwise!
EDIT: Right, here goes... finally!
Really liked it in places, and kinda didn't in others. I liked the starting section, the mix of tall elements, speed and diving close to the ground worked really well. The overbanks were nice too. My only criticism is that it feels like it's going to stall into the MCBR. From there the MCBR trims more speed off and it felt it like it was crawling through the first few bits of the second half. The second half was nice, I liked the interaction with the ground and tress and the low level helices and hills. However again, the train really crawled onto the brakes. My advice would've been to let the train go through the MCBR with a bit more speed and that would've made the second half really punchy.
As for the building... It was mostly smooth, jerk/pump free, really nice for a hand built invert. I find them really hard to get right in terms of smoothness and flow and I think you just about nailed it. The supports were good and the interaction with the trees and landscape were nice too.
Overall, a good layout, slightly let down by a slow second half. 7/10
Sorry it's taken me so long. This review must work out as roughly a letter and hour!