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

I’m new to ML and have a chance to buy a 333 for 3k from a friend, fully restored by ML (all caps replaced). ML also has an upgrade program to replace the PCB to essentially turn it into a 336. 

Question is, are the 3xx series - given that they’re 20 years old - in the same class as the 10 yr old 432/532 series, or are 432/532 an upgrade over the 3xx series? I wondering if it makes more sense to buy a newer model rather than a 20 yr old model. I can’t really find a positive answer from the forums so wondering if current owners and experts know the real deal. Also, it seems like the H series is a budget version of the 5xx line? What would be the sonic differences between them, if any?

if it has been gone through by ML and updated I would go for it.
the 4xx series seamed to be more of a takeoff from the Proceed line they discontinued. The 3xx will beat out the 532H and is rated down to 2 ohms. It will drive pretty much any speaker.
Thanks. So then what is the proper successor to the 334-336 line, is it that still considered current?
I own a ML 336  I don't use it because it's the worst amp ML every made I use the ML 532 H much it's  more reliably roughly the same sound  in short listen sessions . One may like certain things the 336 does or the 532 H does . After a few hours of play time I would worry if my 336 would die . The 532 H sounds better as time goes own . The problem with the 336 is it will beak down and if you are lucky enough to  get it fixed it will cost a fortune . Avoid the ML 336 it really is a bucket of bolts the 532 H is one of the best amps ML made  and will best most ML amps in longer listen sessions . 
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:
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 .
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.