I sold my Massdrop Plus a few months ago, but I well remember their sound signature.
The T800s definitely have the edge in all technical aspects, such as extention to both ends, overall detail, imaging/separation, soundstage and transient response.
However, they both sound very different, being the MD+ a much more relaxed and intimate experience with a notorious mid-bass emphasis, forward mids and lower upper-treble presence (but retaining a nice sparkle), while the T800s are more in line with a bright-neutral signature, extending way better from sub-bass to upper-treble areas, giving the impression of more air moving between instruments (mids and mid-bass are a bit backwards in the mix as well as, which helps to provide this feeling too).
Also, keep in mind that T800s would be spicy in treble compared with the MD+ depending of the tips used.
In the end, is on you depending of individual sonic preferences and generes listened, but the T800s are more technically proficient overall and almost equally well built and comfortable as the MD+, if not better.