move to a floorstander from Harbeth?

What amps have you had the most luck with partnering with Proac?

audio research tube amps are the best (stewart tyler used them to voice the speakers) but uber smooth solid state works too... hegels, benchmark ahb2,  musical fidelity (nuvista series especially), top tier d/gan fets can work great too... proacs are not hard to drive but have a very revealing treble response, so lower level solid state nasties won’t pass the ear test

there are suggestions of atc’s.... they are excellent transducers but be careful with those if you’re a noob ... even more revealing tweeters than the proacs and generally quite inefficient, hard to drive loads... it is one of those speaker brands that you need amps 2-3x the cost of the speakers to do the speakers justice ... compared to proacs, i also felt the atc’s were every bit as transparent and see-through... but the atc’s did not image nearly as well, due to their chunky wide baffle designs on their larger models

You should be able to find SCM40s used under $5k. There’s one on The Mart right now. 

https://www.usaudiomart.com/details/650271862-atc-scm40-passives-cherrywood/

mashif, yes I saw those. A bit above my range, could maybe talk them down. The only thing is I don’t think my belles aria will come close to cutting it with those so I’d be looking at 2 upgrades at once…may be worth it to wait and do that. That’s what I have to figure out - something like the Graham now or wait for something like the ATC when I have enough for an amp upgrade also: 

I own both a set of harbeths as well as meats both levels up from the ones you have as well. A really good friend had a set of atcs and I am familiar with them.  The ATC are a studio monitor and sound just like that accurate but dry. The mid-range on the harbeths is likely better that the others I have the fives. The top to bottom balance is very nice on the meats I really like them but I have them on a home theater system so I have never put them into a really high end system. So in that respect hard to say what you Will find . Also I have another great friend who ran spendors  they are very nice as well they take some power.  Personally all of these speakers are very good but all at the same level. More of lateral move. Also personally if you find the harbeths hot on top you have problems elsewhere. Wire likely I am not familiar with your amp or streamer. But I would first start by trying a power cord. If you want to get a better speaker go up the food chain a bunch. On my big system I did exactly that and was very happy with that change. You are all in about the same level what you are looking at so very small differences. 

OP

I would suggest you take a listen on ATC SCM 40 floor standers. if possible, do a long-term listening. you have posted your gear, and you got GOOD ones

the ATC floor standers are very good IF you pair them with a Great amp

I only have atc sm11 powered by Pass amps and all i can say is wow! Have not heard a BELLE amp but the reviews been great. so Yes, I can attest that ATC floor standing speakers are worth its weight BUT only if Powered by an AMP capable of driving it. If you decide to get the scm40 and you think you need more power, then stick by the Pass amps in the 250W or more. the 150 only suites the scm11/19

Good luck