I have a 50 now and have owned a couple of the 100 Watters, and even one of the 40... (even that one was pretty good through a proper cabinet. I think they are very very solid and sound better to me than many amps that are much more expensive and or more "coveted".
Recently had a Silver Jube 2555x and my DSL50 sounded much better. Also compared side by side to a JVM410 and the Dsl was better.. It is not as good as my 82 and 83, 800's but better than 2555x and JVM.
Also , years ago I had a Wizard Metal X and a JCM 2000 100 watter and at a jam with some friends at which I was all amped to show off my Wizard. Unfortunately for me The lowly DSL 100 sounded better and sent my Wizard Metal packing.. I witness a similiar thing when I see my friends' band play. One of them has a Dsl 100 that I helped him dial in,( they can sound a bit dull and or harsh if you don't dial them in right) and the other one plays a Wizard MC. In the live mix, the DSL sits better every time.. ( I have seen them no less than 10 times) They just work. It may may not be a premium vintage Marshall , but they get in the ballpark and do a solid job.
Just my observation and experiences. YMMV.