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...
dhcod
I now have both the C7s and the M30.1s in house. Don't know that I'm hearing a $1200 difference. Giving up bass for a degree of purity of midrange is a tricky trade.
I echo what some of the others have said. I am not sure it is a worthy upgrade if it is in fact is an "upgrade". You will lose the bass to gain mid-range which may or may not be something you want to do. I owned the C7's for a month before returning them for 30.1's. My musical tastes are soft jazz and female vocals so 30.1's work well enough for me. For more dynamic rock music, these speakers are so lacking in bass that I am thinking of supplementing them with a subwoofer. If I wanted to upgrade from the C7's I would jump another level to the SHL5's or the pluses. 
After further listening, I'm thinking it is an upgrade. I feel like the purity of voice and instrument has grown on me and swapping back the C7s is a bit unsatisfying. Definitely hear more of an edge to the vocals and in general everything is a bit looser. I don't listen to rock at all and that's where the C7s are as good or better. For my electronic, jazz, blues, folk habits, I think the 30.1s are a nice upgrade since I have the $1200 to spend. If I didn't, I probably wouldn't go into debt to get the 30s and based on everything I've read about the SHL5s, they don't fit my needs. I'm set for now.... until we move and I have room for Quad ESL57s again.
Additionally I must add that low level listening is way way better with the M30.1s. I still have the C7s and side by side it’s an obvious advantage.

Just trying to help others who are considering this upgrade.