I have a few sets of 10 gridseeds.  They were advertised at 3.3 Mh/s per set.  My actual hashing speed is 2.84 Mh/s, which is about 86% efficiency.

Are the new ASIC's advertised hashing speed estimated?  Or have they been verified/tested as accurate speeds (e.g. 54 Mh/s  for the War Machine)?