The Boom Theory snare arrived today and the Smartrigger hats with Pintech RHC100 a few days ago.
The Boom Theory snare looks, and plays like an acoustic drum - it triggers perfectly from the centre to about 12" with the Roland, (as I had been told it would - something to do with the TD20 module being set for the Roland Pad diametres). It triggers rim perfectly. Works perfectly with the ddrum4 SE and sounds so perfect when I have it going into the Tom trigger input - side by side the tom sounds are amazing against the TD20. I will need a Y cable to trigger rim and snare, but that will be easy. I will definitely be getting the rest of this kit - it looks stunning, looks like a drum - the pad noise is about the same as the original cast precision pads.
Smartrigger Hats work very well with the TD20, and trigger open closed fine using the RHC100. Again I need a Y cable to use it fully with the ddrum4se but I think it will work a treat.