I was going to write in earlier but I wanted to get a few responses in here before I said my bit.
Practicing and sharpening technique is certainly part of improving HOWEVER, I think it goes largely unsaid that it's good to also recognize who you are as a player. It's a necessary distinction because, for example some players are crisp (Michael Romeo, Jeff Loomis, Paul Gilbert) and some players are loose and maybe even 'sloppy' (Joe Perry, John Mayer, George Lynch). A lot of times people get a 'grass is always greener' view of playing and they just want to sound like another guy because they don't like how they sound. There's some degree of slop and tightness that comes with practicing, but everybody hears and interprets music differently, so it's normal for anticipation of the note to vary (aka, behind, on or after the beat); likewise, you'll find examples of every different version of this concept among different accomplished guitar players.
Not to sound overly nebulous... my basic point is, you should be aware of how you hear music and how you want to sound, and just because one of your techniques doesn't line up with someone you idolize doesn't necessarily make it a bad
thing. Reb Beach took to doing the 'two hand tap long stretches' as a crutch because he was having trouble covering them with one hand and as a result 1.) accomplished his goal 2.) ended up sounding very unique by doing it. Another example is when you listen to the raw guitar tracks from early Van Halen albums, there's a ton of slop but the way Eddie spreads out how far before or after the notes is innate in his sound and those songs wouldn't feel the same without it.
Not trying to sound all 'self help book' or whatever. All the advice in here is worth listening to, just don't get to tied up in playing like other people do at the expense of your own personality.