i've had a td 20 for a few years now upgraded from a td 6 which i used at the time to trigger reason drumkits.
the td 20 and i have a love hate relationship. on paper it sounds like a win win combination. mesh heads/silent realistic hi hat, substantial size.etc etc. ymmv but for me, the pads in trying to be too realistic are prone to being flaky at times. hitting at full force sometimes does not produce a full force sound. the hi hat is for sure its weak link. the actual mechanism is very lo tec and also prone to a whole lot of wierdness at times especially with half open hihat sounds
the expansion card for the unit made things a bit better for sure but overall in my opinion the sounds are dated. at times very difficult to fit in a mix when recording with them. live gigging when they are cranking through a pa, they seem to be ok but, i have only done that one or 2 times since i've had them.
i hate to admit, i also think i got better results with the hard rubber pads. there was no unknown with them. hit it hard get a hard sound.hit soft and get a soft sound,less mistriggering
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remember, the td20 is a few years old now. i recently spent some time in a music store with the td9 and also the td20. i enjoyed the td 9 more than the 20, newer sounds on the 9
ymmv x10