Harbeth 30.1 upgrade from C7ES-3 Question

I bought one of the last sets of Foundation Stands for the 30.1 in anticipation of one day upgrading my C7s but I haven’t been able to pull the trigger yet. I’m interested in general whether this is a slam dunk upgrade, but specifically if I may not get the bump because I listen in the near field. In other words, does my listening position decrease the impact of the benefits of the 30.1? Or maybe it the other way around and it’s an even better upgrade for nearfield listening? Buying used so a demo is not an option unfortunately.

I've enjoyed the C7s for three years now. I listen to all kinds of music except not much rock and classical. Jazz, blues, gothy folk electronica in heavy rotation these days. Thanks in advance...