Is there a point of diminished returns with amps and Harbeth 30.1s?


I’m currently using Herron M1As with my 30.1s and I’ve upgraded the rest of my system (Aries/Fatboy/SUT/DL103r and Lamm pre and phono) and each upgrade has been VERY satisfying. So is it going to be worth spending $5000 or so on the used market to upgrade the Herrons? Any thoughts as to whether I’ve reached the apex of amp/speaker performace for the M30.1s?
dhcod
I have forgotten if some users have been banned for posting some issues they experience with their new speakers. Issues such as glue marks on the main driver and defects on cabinet etc. 
This is an interesting issue when you think about it. It’s tough to conceptualize a business creating a public forum that includes people complaining about their products. I would think somewhere in the forum rules it probably states that matters such as those should be handled directly between the customer and the company. Or at least I’d understand if those were the defacto rules.
This is an interesting issue when you think about it. It’s tough to conceptualize a business creating a public forum that includes people complaining about their products. I would think somewhere in the forum rules it probably states that matters such as those should be handled directly between the customer and the company. Or at least I’d understand if those were the defacto rules.

Yes that’s rather true as most companies would want to protect their image and reputation. However, there’s less transparency with such practices especially when the complaints are genuine. The member who once posted issues with his new C7ES3 was a friend. That post he made on the forum was removed by the moderator and I am not sure if he was banned from posting on the forum for couple of days or weeks. There were others who experienced the same, and just lately another case resurfaced as the owner highlighted his plight on a British forum.
@dhcod - Just remember that it doesn’t matter what anyone else hears, claims to hear or claims to tell you what you should hear. All that matters is what you hear in your home, in your system. Then you can relax and listen to beautiful music while others are too fired up trying to push their views onto you. I was a conservatory-trained musician in my youth and one thing I learned is not to assume someone else cannot hear something that you can’t.
Thanks @chayro! I’m plenty old and have been doing this for so long that I do know that. Also work tangential to the music business (feature film editor) and I have conversations with mixers and engineers all the time about how we all hear differently!
first i will say harbeths are excellent speakers, even great speakers

that said, the man behind the company is a first rate capitalist (no shame in that), uses many modern tools of marketing to maximize economics of his venture... including setting up a ’user group’ that effectively sings praises of his products (and quashes negative comments by and large, as well as useful discussions of ancillary gear)... he personally ’moderates’ the group, and posts actively as a participant, so it is heavy hand employed there

as for the ’offer’ of a blind a/b test, it would have been one that he controls, so grains of salt taken there

finally, a few years back, i have personally (with help from my son and a good hifi bud) done a blind a-b-c test, which took some doing, with my son doing the switching and db level match, using two sacd tracks - comparing an audio research vt-50 tube amp, audio research 100.2 solid state unit, and a w4s class d st-500, running into harbeth shl5+’s ... we could pick out which amp 6 out of 6... treble detail and imaging was different, bass tightness was different, midrange articulation was different...

bottom line, excellent speakers, pedantic and self serving owner, the user group is kool aid drinkers only (dealers, inexperienced or lazy fanboys), other discriminating, experienced, intellectually honest/curious folks usually find the b-s factor too high to stomach