detrimental? i thought they were when i was in denial that my FTP was lower than expected.
The local loop (Central Park) has 4 sections of prolonged descents (one of which is a S-bend) and a few bumps here and there. When i couldn't do ZCI at 265W, i blamed the course for not being ideal and wanted to use the NP number for what i got each interval. Now that i can average 290W for 35' without going all out, i think it's an ideal place to do the test. That S-bend is still annoying as the only way to carry through power at full-bore is to cut across two lanes, but it's not bad when i do my intervals at night.
more importantly, the only thing the course needs is that you don't have to stop for anything. learn how to produce power on the downhills and meter yourself on the shorter punches. A histogram of the 35' shows that >80% of the time was spent between 260 and 330W.