Yes I am a Harbeth owner of a C7 Es3 bought them in 2007 with a 4Bsst amp and BP25 amp
I love it!
Hartbeths are generally easy on an amp with higher than normal impedance over all, so one would not think of placing a high powered amp with these 2 way speakers. Here was my reasoning behind this. I listen to a lot of classical, especially choral and chamber music. There are many that love the sound of Harbeths with tubes and I can see why - However, I hate to admit it, my love for harbeths comes because of a slight coloration of the sound of the speaker in general: a great mid range but a gentle top end. Tub amps "enhance" that sound. after trying some tubes - it really was too much. As a musician classically trained, I know what it is supposed to sound like at least to my memory. It sounded great with the tubes but it was too romantic for my tastes - Lovely upper base and mids but the bite of attack in a string quartet or period instrument Bach string concerto was lacking. I tried a Bryson amp (the 4B) and loved it. The reasons are more theory than anything: The power of the 4B gave the speakers the pep that was needed in the top and bottom giving it the balance that was needed and the bite was back. The 4B also allowed the Harbeth to still be a champion in the mid-rang. Large orchestras were "large" and the space was there as well. The base tightened up and was more realistic sounding. Yes 350 w is way overkill for a C7 but I don't have it for loud listening, because I don't listen to music very loud and my room is medium size - but the power brings with it an ease to the music that is very nice - I never turn it up high because I don't want to replace a radial driver and the very true fact that Harbeths sound best at natural levels - they are not a loud listening speaker. I attribute this to the way the cabinets are designed. I really enjoy this combination and I listen every chance I get. After 7 years, I'm still delighted to what I listen to. I needed that thwack/thumb you get with a base drum while listening to Rite of Spring so after 2 years I added a nice sub woofer to the mix and loved that addition. Organ music sounds great now. I was lucky and was able to balance it out fairly well - it took time and patience (on behave of my wife) but I got it dialed in nicely. I believe that those British monitors need a good amount of SS power to sound there best selves. You will love how truthful they (both Bryston and Harbeths) can sound. Someday my dream is to get the M40s and pair them with Bryston of course with a bigger room.
Enjoy