I'm agree with some of things that Ken said.
For me it's also important how the song sounds. If it's a bad song, I really don't care how awesome it's the solo from it. Becomes useless if the tune sucks and the probability to listen this twice will be zero.
About the bands....hmmm....I prefer guitarists who release solo albums. I never had a special attraction for the guitarists from bands (probably I'm more a guy than a girl
).
About the shredder.......I really don't care who the shredder is!!! For me it matter how those techniques sounds in his hands, what tone he chose and how good it fit his solo in the song. Sometimes a "too burning" solo can ruin a good song. I think it's very important for a guitarist to make the solo in the way where he can show his skills but to remain in the same "movie" with the song itself.
Also, I really appreciate the guys who don't have a fake attitude on stage. From my point of view the edge between to be cool and ridiculous it's very tiny. It's better to be natural and if you are a good player, people will like you no matter if you will jump around on stage or not.
If you have a fake attitude on stage probably the percent to attract more people (superficial people from my point of view) will be bigger but they will appreciate you more as an image and not you as a musician.
As a conclusion, girls can appreciate guitarists that shredd but it depends how they do this and not who do this