I just realised something when I read makomk previous post (thanks for the info, by the way!): the unit MHash/s is not self-explanatory! To do one check if a nonce is golden or not, you need two calculations of a SHA-256 hash. When I gave my synthesis results previously, I interpreted 1Hash as one calculation of sha(sha(.)). Does everyone do the same or does your unit equate 2Hash to sha(sha(.)) ?
It seems to be standard to list the number of MHash as the number of total sha256(sha256(data)) operations just like you did - certainly that's what I've been doing. I get the impression this dates back to the early days of bitcoin. It's possible others haven't been doing it this way of course.
Edit: Also, after a slightly tedious 4-hour build process, Fmax=109.29MHz and 97% resource usage for the fully-unrolled DE2_115_makomk_mod on the EP4CE75F29C7. Might be able to get it up to 110MHz with the right options, but I wouldn't bet on it.