I would say n+2 is easy to get, but no more. You start getting very high b+f. I have calibrated by the BTZS method, but in zone speak a SBR of 6 is similar to a "n+2" situation. I gotta tell you, is a nice film but I did not see an advantage over TMX to spend the extra money on it. Reciprocity for TMX 400 is not bad, and I rarely shoot at more than 3 or 4 seconds, so the only advantage ACROS would have does not justify the extra expense. My experience, dont bother buying it.
I am about to use Barry Thorntons Exactol Lux on it (finer grained version of DiXactol. The instructions state that Acros becomes very soft in this developer, so advises extra care. Sounds like if you treat your film with care (well, obviously who doesn't ?) you should be fine...