Had one, wasn't crazy about the artifacts that it added to my tone. Something was there I couldn't gel with it but I have been meaning to try it again 8+ years later.
My go to is my DOD YJM that has the Outlier mod. (guy on metro forum from years back) and I really like the JHS Bonsai right now too. Pretty much anything can work for boosting Marshalls though. So many options. It may be a bold statement but I prefer the sound of boosted amps to amps that have the gain built in.