If we can discuss the OP...
@Ross - I think that's a good question. Most of my first year Mt Etnas tasted the same for me too. MBVS, St Rita, Hardy Chicago, Bari, and Malta Black whether a Mt Etna or not. I wouldn't be able to tell them apart without the tags except St Rita which always seems to be wopsided (Honey Boo Boo anyone?). Salem Dark and Sal's GS were a little different with Sal's GS having a somewhat peachy flavor sometimes and Salem Dark having a little something that I don't have the words to describe but very good.
@nkesh099 - I used the search function but haven't really found any comparisons. I read that Navid's Dark Greek seems to be a very good with similar productivity and taste to a Mt Etna but "with something extra." "MBVS on steroids." Would you agree with that? Do you have any observations that separate it from other Mt Etna types? I suppose I'll never truly know unless I grow it myself and it is on my ever expanding wishlist but it is nice to hear other opinions.
Does anyone know? Do the Mt Etnas seperate themselves more as they age with flavors, hardiness, growth habits, etc. distinguishing themselves more?
I'd still be hearing comparisons of the various Mt Etnas from those that have more experience with them.