A very good acoustic and electric guitarist with one of the top musical acts in the world, works with a metronome on a regular basis. (I know him a bit, but this info comes from a mutual friend who knows him well.) He say's it tightens up his timing and his playing. He claims that his rhythm and leads are more spot on within the band's live show's and his overall playing, too. ( He plays solo and with his own band, also.) I've been trying it for 2 month's on a daily basis for 30-45 minutes a day. I play single notes to every click... one at a time. (Sounds rudimentary but it seems to work.) Then I graduate to more intensive lead patterns, chording and fingerpicking. And, I vary the speeds of the meteronome from very slow, to eventually, very fast... and adjusting my playing to the tempo changes. I'm noticing GREAT RESULT'S!!!