Being a owner of Keiths M-150 amps I would say I am very happy with them. I have owned for over 2 years now and no problems they are bullet proof and well built. Also he offers EXCELLENT service which in my IMHO is worth its weight in gold nowadays. He will go out of his way to please his customers . I have had my amps upgraded and he charges very little to do this shipping ,parts, labor and the results are out standing. He takes pride in his products and it shows in the results. The amps in my system disappear and only the music is there. They will tell you the truth also they will not cost you a fortune in the electric bill as they run very cool and efficient. They also are compact and take very little room, they are plain looking compared to most every other amp out there but the real beauty is on the inside.