So here is what I got on Digital Ocean lowest spec machine (1 core, 20GB SSD, 512 MB RAM, Ubuntu 12) with a bare NGINX:
34178 fetches, 10 max parallel, 683560 bytes, in 5 seconds 20 mean bytes/connection 6835.6 fetches/sec, 136712 bytes/sec msecs/connect: 0.0445469 mean, 0.937 max, 0.021 min msecs/first-response: 1.41242 mean, 101.975 max, 0.257 min
And with the full nginx->postgresql with postgis searching for speed limits around submitted location (but only a few limits present in db for a moment):
5574 fetches, 10 max parallel, 6.22058e+06 bytes, in 5 seconds 1116 mean bytes/connection 1114.8 fetches/sec, 1.24412e+06 bytes/sec msecs/connect: 0.0561055 mean, 0.37 max, 0.023 min msecs/first-response: 8.68285 mean, 187.733 max, 0.812 min
So it got from almost 7k to 1k per second, still that's from the different universe compared to what IIS/.NET would do for me, and look at the machine spec! Plus, $0.0 for nginx + $0.0 for posgre/postgis - pure win!