I'm still waiting for people to just quit. I know a few people irl who just invested a shitload of money without even knowing the basics of a computer, without knowing what bitcoins or alt-coins really are.. they all wanted to get on the wagon and the only ones that are really laughing with ether are the ones who bought in at the ICO and ATI. ( they never sold so many video cards ) ATI is even worried with the amount of video cards that will drop back on the secondhand market by the end of the year.
IMHO, with the Nvidia cards I wouldn't mine ether anyway... but zcash .. or split the rig in multiple pools ETH/ZCash and do some more new alts to get some of those coins in case their market shoots up.
It has been said many times before, not every card is the same, some mine faster than others. Then there are different memory types., Samsung, hynx and others. Also when ppl reported their speed the hashtags difficulty was probably lower than it is now. So I think you are doing great at 55 mh/s