i haven't tried the fx700 , but imo the 272 is better than the eq-5 - and if as you say the zo gives 272 a nice bass boost then i can see your eq5 going to the fs threads soon
i have said it before and i will say it again - i think the 272 may be the top iem for the prices up to 250$
I gotta admit, I'm growing more and more fond of the highly detailed and crisp clear presentation of the 272's, as if I'm enjoying the ER4S with a thicker presentation and in a much better shell. Considering that the Zo leaves me with little to be desired in terms of bass, I'd say the 272's may have earned themselves a permanent seat, right besides the e-Q5 and FX700. Though I'll give them a few days time before that's official.