I "destroyed" my Y axis trying to print Honeycomb at 80mm/s. Problem wasn't much the speed, but the dreaded honeycomb. They look cool and are definitely solid, but they move so much faster while printing infill, it shake the whole machine badly.
But on a positive note, I printed one of those geared heart yesterday at about 65mm/s (http://www.thingiverse.com/make:195812) and it turned out great. The surface quality isn't the best, but as you can see it's quite "OK".
I mainly print functional parts and I wan't them fast, so my print speed isn't the best if you want perfectly smooth surface and what not.
By the way, this is done on a Wilson TS, so should be better on a Wilson 2.