I have a modded MIM strat, designed for blues and rock, and want to get another guitar, one more suitable for metal. Which should I go for, the EBMM John Petrucci 6 or 7 string guitar with peizo?
If the only choices you're considering are the 6 and 7 strings, uh.. Why are you asking others :P the 6 and 7 stringers are really just a matter of personal style/preference; anyone who'll tell you "they know what's better for you" in this, is a liar.
which ever one you feel most comfortable with, with the 7 string you got that extra b string so you could experiment with it but with the 6 string you will have less time struggling to get used to the extra string
I think when you are getting into string numbers you should really only be asking yourself what to get. I mean, if you want to play music that uses the extra string, then of course you would get it. If you are at the point where you are choosing your own style, the only reason why you would buy anything is because you want it and you have a personal reason for getting it.
no you can use it to just experiment aswell you can still play normal six string chords on a seven string it would just seem weird
Try out a seven string and see how you feel