Is there a certain guitar that works best with this software?

Hi, Im test trialing the midi guitar 2 software via the VST within Ableton.

The function of MIDI Guitar 2 is not that great. I am playing with a Silver Sky plugged directly into the instrument in of an Apollo Twin.

The Silver Sky has a low output vintage style pickups, would MIDI Guitar 2 perform better if I boosted the signal with a preamp such as an LR Baggs unit?

I am a MG2 owner. It works great with all my guitars. However they all have same pickup - single coil - fender style. I have observed that if I use position 4 or 5 (Neck or Neck+Middle) I got better results.
It’s important to play clean and more depends on the soft synth you are using. Like all software needs tweaking and tuning to match your gear and playing style. The signal input to MG2 should be clean (no effects or similar) and signal should not be weak. Maybe adding a preamp might help but with single-coils I never had to. Plug in my Audio Card, setup correctly and I’m done.

Hope this helps