I used to be Legacy only, but branched into MTH recently because they had a lot of items I wanted that weren't offered by Lionel. If you're getting even one MTH protosound 2/3 locomotive, definitely, definitely invest in a DCS system. Running PS2/3 in conventional is like running a Legacy in conventional. You're missing so much.
Can't speak for those specific units, but I've never been outright disappointed in an MTH Premier locomotive. Detail is always good, especially the steam engines. Also really like the feature that I can change the sound set if I don't like the one from the factory.