I don't know much about roland, but are these toms Dual Zone? If so, it may be overkill, as I thought only the snare is dual zone on the DM6.
PD80's 8" or 6"?
For me, I'd go with Alesis, then convert the head to mesh (roland mesh). But then again, if all things are equal, why not just start with roland?
I think their piezo assembly is different (cone, right?). If so, it may not work well with the DM6 and it's limited adjustable settings.
my two cents...