No doubt it's a very fast course, but I agree that it's probably not much more than 100m off. The times are very comparable to what most of these athletes could run on the track right now. Rupp right around his track PR, Kinsella and Kiptoo's prs are 28:58 from 2 years ago so no doubt they can run AT LEAST 28:40 on the track right now. Mineau has a 28:48 pr (I think) and ran 29:06 at regionals. 10th place G. Heath and 5th place Derrick went 3/4 at pre-nats, Diego Mercado and Klotz ran ~29:30 at regionals and can surely go faster than that on a track (I believe both + other Mercado have PR's in the 29flat-29:20 range). 21st place E. Heath ran sub-14 last spring, 22nd place D. Shackleton placed extremely high at USA XC champs last winter, #26 Schmitt ran sub-29 last spring, 30th place Karlsson ran 29:28 last spring, 36th and 56th place Houck and Ahlbeck are ~9flat steeplers, etc etc etc.
I believe many people do not really realize just how strong the west region is. Yeah this was obviously the fastest regional course anyone ran this weekend by a nice chunk, but it's xc - who cares about times? But it would not surprise me if a majority of the top-30 guys (who run a healthy 10k in the spring) run faster than their regional times.