I threw a set of the ASP pullies (crank and larger alt) on when I did my cam swap. I think that it was worth while, the engine revs much faster. My voltage gauge fluctuates a little more than it used to, but I also have efans and an amp. No problems with dimming lights or anything like that.

 

I had Allen put mine on when I got my tune last month, we did a dyno run after each mod, I think I gained 5rwhp and 7rwtq from the pulleys. I haven't had any problems with mine so far.