Slash's legato was the making of me, I used to sit and listen to his soloing over and over to work out how he got the speed and the tone at the same time. Subsequently whenever I play something fast in a solo I tend to do very little picking (although this is starting to change now.)
Slash made me realise how important it was to have a distinctive tone - its one of the things that sets him apart from many players - plus he has a tone that matches his style and anyone who can acomplish this deserves much respect. He also bears in mind the melody of a song when soloing, and thinks about how the chords behind the solo affect how the solo sounds....for example: try playing that awesome scale-based run in the middle of the Sweet Child of Mine solo without the chord progression behind it and you'll find it sounds very different.
'There's no such thing as bad weather, there's only the wrong clothes...'