zenaxe
Fractal Fanatic
Sadly, or rather joyously, depending on your perspective; there's a lot more differences between individual instruments than their sound. As a result, having played around with a number of them; I have found these types of tools variable in their usefulness and largely unsatisfying on the whole. To the point where I am for the most part not particularly curious about them unless the technology evolves a bit more and even then would expect it to be via a genuine physical interface like the variax, etc.
Since most players tend to not interact directly as much with their amp during performance and the general role of the amplfier in the chain being much more of a pure signal processing type of device, the amp sims tend to be a much better replacement technology than guitar sims... and can even be better in some ways.
Likewise, you find that amp simulations tend to get the most meaningful criticism or run into the most clear limitations at the other end of the spectrum: again, where they have to interface with the real world: amp in the room, where the simulator cannot close the physical loop at the speaker cabinet pushing air.