The whole thing about triggering is timing...when you play drums and are rolling, shuffling, doing quick ghost notes on dif drums many times a second, latency becomes a huge issue which is why electronic drums are still not as widely used as acoustic, especially by serious players.
The folks at Hart recommended the TMC-6 because it uses the same trigger circuitry as the TD-8 and TD-10; it doesn't have any on-board sounds which is why I connect it to the XV-5050.