CakeAlexS
Almost anything that goes through the Overloud TH2 effect sounds like a rock guitar IMHO. Find the right guitar patch and off you go. As far as performance is concerned, well that's another matter :). I tend to wear a wig when playing...
Exactly and it is, from what I've seen, a somewhat known technique with about the best results you can get for synth based "rock" guitar. You treat it like you would a regular guitar signal. Find the cleanest, most realistic sounding guitar synth patch you can then run it through a GOOD amp sim. Just like plugging a real guitarist on a nice guitar into a good amp or stomp box into a clean amp or guitar into an amp with an effects processing loop.
That's why I brought up AAS Strum. I haven't used it because... well guitar has been my life for the past 25 years so I don't need it, but it has a crapload of controls and from what I've seen on some of the vids it is about as realistic as you'll get out of anything in Sonar. A lot of it is acoustic sounds but there are some more electrical clean sounds in there that would definitely be a useable clean signal emulation that could be easily processed by a good amp sim like TH2. Even still if you have ever plugged an acoustic guitar into a high gain amp or with a stomp box into an amp the tone is freaking delicious. It's the damned feedback that causes problems.
I used to have a semi hollow body es-335 clone that had a lot of acoustic characteristics that I would use heavily distorted and it was AWESOME... until I tried to get to stage volume. Then the feedback was just too much to deal with... not to mention all the other metal skids would make fun of me for my grampa guitar, lol... but screw them.
The point is that AAS strum was designed to have as much human characteristics as possible which is the most problematic part of creating realistic sounding guitar parts with synths. I could see it being quite effective at at least giving you some good quality metal gallops and heavy power chords if you a) chose the right clean sound from AAS, b) learned how to fiddle with all the humanizing functions in it, c) wrote the part like it would be play on a guitar (which should be easy as it has a fretboard input and you can punch in chords and choose from different fingering variations... I think, which is VERY important to specific tones) and d) ran it through a good quality sim.
Still it is NOT going to be as good as a real guitarist but for what's within the program I'm guessing it is probably about as close as you'll get.
I'd be interested to see how this turns out. In fact I may try some tests of this myself.
Cheers.