Happens to everyone that uses at some point. Many people use their poison of choice, and maintain "normal thinking" while doing whatever the action is at the moment. Eventually, they either have to use more stuff to get high and/or their brain cells start popping left and right, and then they turn into a mess, and that's when people really notice that things have turned for the worse. For some, it happens faster than others. Sometimes because people will just start off taking more than another person.
Stevie Ray Vaughan is a good example....started off as just an outright awesome player, listen to "Live at the El Mocambo." He's powerful, on top of things and just outright killer. Then, listen to the second disc of "Live in Montreux" recorded in 1985, which I believe is just 2-3 later. His playing is shaky at best. Hitting wrong notes, ideas not being executed as they could have been like the former video. He'd hit big time, upped his dose of coke enormously, and was falling apart.
Eventually he cleaned up (around late 86 early 87 if memory serves) and became almost a better player than he was when he was discovered.
Not too many guys actually maintain the intensity of their "using days" when they clean up. Eddie, from what I've heard, seems to have lost an edge-but I'm nowhere near the EVH follower as you N_A, and wouldn't be able to say for 100% certainty.
I would say EVH has probably lost an edge but in his defense he really hasn't written anything in along time-I'm not counting the 04 tunes cause he was trashed at that point and Sammy has said he didn't want to be in the studio with him so it wasn't really a cohesive effort.
Ed's songwriting was great in 95 for balance and 96 for best of volume 1, his playing was great in 98 but his songwriting had fallen off.
What ed needs to do is get a producer who will "produce" the band, not let Ed do whatever he wants...no playing bass, no engineering, no mixing, no co-producing, no writing lyrics, no playing drums...just tell Eddie "get in there and wirte some kick ass music, play your guitar or keyboards but just do that." let Sammy or dave write lyrics, melodies and sing, let Mike play bass and sing back up and let Al play drums. the band with Dave or with Sam was at it's best when everyone could be themselves and do what they did best not when everyone is doing what Ed feels they should be doing. If they can do that again they'll be fine, if it's "the eddie van halen" show it's gonna be a mess like VHIII was.
I dont' know if Ed can play or write like he used to, he's older now and he's been through alot. The porn stuff he put out last year was a waste and he played for about 10 minutes at NAMM and it didn't impress me at all, he had no direction with anything he did. The guy's been a mess for so long it's hard to say if we'll ever see the real ed again.
like I said, it might be easier to have him and alex sit down with Glenn Ballard who's been thier producer for awhile and go through some of the leftover tracks from the last 25 years and put out a compilation of that stuff. I know they have a ton of stuff from both era's so it wouldn't be that hard, most of the stuff is recorded, mixed and ready to go. They'd jsut have to polish it up a bit and it'd be good to go.