Of course, it's the player and his de-tuned guitar. But any of the modern modelers can get you here today.
Yes, there are differences - but they're all good - Fender, Helix, Fractal etc.. Focus on the audio reproduction side of things - that's where the major gains are to be had. I still rely on a good collection of guitar cabs because I find the sound just right. But going forward, hopefully a good "FRFR" will come out!