The MC501 (Stereophile review), MC452 (Enjoy the Music), MC462 (Stereophile) were all highly praised and highly recommended by seasoned audio critics.
(I own a MC452, driven by a ARC Reference 3 linestage powering some Yamaha NS-1000Ms') And the Yamaha's big beryllium midrange is unstoppable. Jazz, rock or classical; they do it all well. I bought the NS-1000's new in about 1985. The only speaker I thought that came close to their sound in it's ability to satisfy was the B&W 802 and 803 diamond series. .....Yet I digress.....
The McIntosh sound is exceptional. I don't need the cosmetics or big blue meters, or the shiny handles; I'm not impressed by its' 105 pound weight or that Mac's hold their resale value fairly well; I bought and loved the MC452 for it's glorious mid-range, it's sonic detail and it's ability to reproduce every type of music with speed, delicacy and slam when needed. ...And McIntosh equipment is very well-built. Look inside them: they're very well thought-out.
Output transformers: I listened to many combinations, whether they had output transformers or not. I can't detect any sonic signature with output transformers. Some readers may think I just don't know what I'm hearing. I have been critical listening since I was teenager, and I'm 59 now. Of course it's true all our thoughts and musical emotions are filtered through our own personal psyche and subject to opinion. Many things can't really be proven or disproven (i.e, is this mains cable improving or detracting from its' musicality...?)
I've heard some audiophiles even question Ohm's Law. By the way: you can't.....
I find the ARC Ref 3/ McIntosh 452/ Yamaha NS-1000M combination so satisfying that for the last few years I've had no desire to "upgrade." Everytime I listen, I just feel, "I can't believe this sounds so good"