Again, and not enough can be said for sample-playback workstations whose programmers have put a ton of effort into the various nuances of a guitar sound (electric or acoustic). It requires great samples, layers of samples, and awesome effects, to come up with a convincing guitar patch.
Then, take Philbagg's instructions and utilize them in your sequencer. Trying to memorize all those intracacies playing "live" would be quite a feat, because you'd have to roll your hand over a chord one way, then roll it the other way, and then change chord positions (of course), and continue this exercise throughout, along with pitchbending.
On my Kurzeil K2500XS, some of my guitar patches utilitze more than one slider on the workstation to adjust the loudness and depth of the plucking sound (using a different sample within the layer), and another slider for the depth amount of reverb, while also the hardness of the velocity attack changes timbre [pronounced "tamber"](another sampled layer).
Of course, not every guitar note by a guitarist has equal amounts of those attributes, so attempting to play and adjust your sliders "live" is really next to impossible. Routing continuous foot pedal controllers to handle those jobs could help much so that your hands are free to play the keys.
Depends on what your objective is. Live, and to impress people? Do everything manually. Recording? Then use the sequencer, by all means.
