The problem with the aftertouch is that it sets in too late... you have to press quite hard... breaking fingers is perhaps an exaggeration, but I suppose it is all about how you use aftertouch... playing a piano is not the same I think, because a piano does not have "aftertouch" per say?
Usualy what I use aftertouch for, is stuff like vibrato ... mostly... and it becomes part of your playing technique using it, thus it's a real pain when you have to press very hard to initiate it, especialy when you play fast sequences... I never use aftertouch to imply effects because I hit the keys extremely hard... besides I don't like pressing that hard... I feel I might break the keys with the amount of force needed to get max pressure output from the aftertouch.... also, in my GT, the lower I get on the keyboard, the harder I have to press to initiate the aftertouch... I'm not sure why that is... if the aftertouch strip inside the keyboard is misalligned, or it has to be played extensively to settle in properly... as it is now, the Aftertouch is useless to me, and works just like it did on the A-800 Pro to be honest... The Velocity though, is REALLY good, and sensitive.... only thing I don't like too, is that it has quite a bit of mechanical noise compared to my earlier Yamaha EX5... it makes a load of noise playing it...
So I'm actualy happy to get the Sub37... I read somewhere that it should be the same keybed as in one of DSI's synths... either the P12 or P6... don¨'t remember which, but that hints me that the aftertouch will be good... also I get a separate pitchbender and mod wheel.... while it's cool for some things on the GT, on others I hate that the mod.wheel is springloaded.
So all in all, I'm pretty well covered in controls with the combi of the GT and Sub37... I'll have separate wheel/mod and combined, I'll have soft/hard aftertouch, I've got a large X/Y pad, loads of customizable knobs on the GT, I got twin D-Beams too ... and when I get my VL-70m I have a breath controller as well... only missing a foot pedal still
Hope you'll like your Analog Four by the way... seems like a capable synth too