Actually physical modelling is more CPU intensive (Although the algorithms used have improved the efficiency in recent years) as it constantly calculating how to get the desired result from the input. (This is the reason it is not used in a lot of keyboards as they just do not have the necessary processing power)
After saying that, when it comes to computers than multi-core CPUs are common these days so each instrument can have its own core. (Something not possible in most keyboards)
Physical is the way to go (I pretty much thought it would be common place by 2020 with the increase in CPU power that was occurring in the 00s) and the sooner the better.

Bill