Mark Levinson model differences : 333 vs 432 vs 532 / H

I have had an 333 since we purchased it new in 1995. About three years ago, it failed, and I had it repaired at an authorized facility for about $2500. I continue using it and have no plans or desire to replace it. It is very difficult today to find an alternative which could have one's confidence that it could drive any speaker you may want in the future.
In recent months, our audio club has had two videoconferences with prominent amplifier designers. I asked each, "should I replace my amplifier?" (One was John Curl, the other the head of Schitt Audio.) Each essentially replied "probably not," and that amplifier design had not changed significantly over the decades.
As far as I can discern, the 333 sounds very good.

Here is a review for the 333:
https://www.stereophile.com/content/mark-levinson-no333-power-amplifier

I have a ML 336 failed also and I'm not repairing it . I also own a ML 532 H much more reliable and for short listening I would say about the same sound but if you are  listening for longer the 532 h is much better . I had the 336 for over 20 years  with my ML 380 s . The 380 s I love ! I never had to bring it in  for repair never a problem , beautiful pre amp .Sadly the ML amps back in the mid to late 90s were  terrible . I had a service guy once tell me I should  not play the amp for too long ! What a bucket of bolts !

I own both amps and the 3XX does not come close to 532 h  ,3 xx is just a bad amp .

No 333 still going strong here after 25 years of use

I have a No.331. Still working...never a problem. I play music EVERY DAY, so you can imagine the hours on the amp. Great amp, great midrange and bass-controll with any speaker.