Meachem is a faster, stronger, slightly more athletic Colston. Colston is a little taller, but Meach has an impressive wingspan also.
Colston is probably still a better route runner, but if he keeps dropping catchable balls then he could lose considerable reps to Meach.
I think Colston has a tremendous heart and it shows via some tough catches in traffic, and he should continue to be a threat in the red zone, but if I had to put 2 receivers on the field on 1st and 10 at my 20, then I think I'm playing Moore/Meach.