The chatter about he Nord Piano has myself considering one. Also the fact that I've seen them priced at $1999.00 on Ebay.

I have never considered a Nord product mainly cause of the price and really like internal speakers for their limited but useful function. One of which is to give the notes some vibration. Which brings me to my question? Why hasn't the major companies added a TRS system to their current models? It would seem an easy addition since they're smaller than speakers.

My assumption is that it's not considered an important enough feature to implement en masse - either by consumers or by manufacturers. It's not something I'd have in my most important considerations if I were DP shopping. That's not to say that it doesn't have its place in some models. I also suspect that it's not just a matter of bolting a vibrating transducer to any keyboard. It has to have the desired effect - that means being properly implemented so that it gives a realistic feeling, and also being fully tested so that the vibrations don't cause problems for other parts of the DP. It may also be that the keys have to be made of a material of certain density to transmit the vibrations effectively. ie. The wooden action of the AG may be more capable of this than the plastic action of the NP. I think it's also worth mentioning that it makes noise so people who buy a DP to practice silently with headphones would probably want to turn it off most of the time. I don't think the arguments for including it on most DPs is very strong. But that's my opinion. Let's see what other people think.

I agree that it may be more complicated than it seems to make it work right, so it's not like a cheap afterthought you can just slap on any DP.

I call it marketing jargon. Not saying it isn't a nice feature, but "tactical response system" is a poopy marketing phrase for bandpassed speakers. Now, if someone actually used "exciters," that might be different.