Re: Does playing a 7-string make you worse at 6 string guitars?
Playing a 7 string or 8 string for a while will make a 6 string fell like a little toy when you switch back. I have no trouble transitioning between 6, 7, and 8 strings, even with drastically different scale lengths. It takes a few minutes for your brain to readjust, but then you are fine. I will say that picking up a 7 string has improved my playing significantly. Scales make SO much more sense on a 7 because your top two and bottom two strings are the same. It is so much more symmetric when thinking about scales that I sometimes wonder why 6 strings still exist. I do like them all though. When it comes to chords, you do have to figure out how to integrate that 7th string, but again, whatever you are doing with your high B string, you can do with that 7th string too, so it isn't very difficult.
I remember being very narrow minded when I began playing decades ago, not wanting anything that differed from a traditional Fender Strat in any detail. After all these years playing, I now like variety. I like to switch back and forth and see how it changes my approach to playing. It seems really weird to admit, being someone who began on Fender Strats and then spent decades playing Gibson Les Pauls, SG's, and PRS guitars..... but if I had to pick just ONE guitar to keep, it would be an Ibanez 7 string.