If you want to future-proof your DX sounds,? I think avoid anything as exotic as a DX1.?? Get a decent MIDI controller keyboard and install a few instances of a VST.?? There is a “bit accurate” version of the DX7 Mk1 called Plogue Chipsynth OPS7.?? OPS7 has two engines per instance (kind of like a DX5) but can only read SYSEX from an original mk1 DX7.? It sounds identical.?? If you layer a few OPS7 in a DAW you can emulate TX816 sounds (8 x DX7 Mk1) and more!?? You cannot do the poly-aftertouch in OPS7 (even if you had a poly-aftertouch MIDI controller).?? I think that there is a chap who now works for Cherry Audio (Tim Shoebridge) who has written a VST utility that emulates “last note aftertouch” or “first note aftertouch” changes..? but not as functional as the real DX1 aftertouch.