www.megadrum.info

Software on your computer via MIDI, are there even any advantages to using a modern module vs a 15-20 year old one? (amount of inputs and quality of built-in sounds doesn't matter)
I've been learning about this stuff and from what I understand midi packets are very small, so I would imagine that I shouldn't expect any serious latency even with older modules. Please correct me if I'm wrong. If that is correct, however, are there any actual reasons why a newer module would work better? For example, a Roland td-25 or td-12 vs an alesis dm5.

Insight much appreciated.

No.

Modern module would have an advantage of having settings for modern pads out of the box (but I think this is irrelevant if you even consider MegaDrum as a solution ).

Modern module may have support for positional sensing.

Modern module may have a built in MIDI-USB functionality - might reduce latency a little bit, but you would have to measure.

You said that amount of inputs doesn't matter, but I think it actually does. In most modules you can't expect every pad to be compatible with every input.