I just took home a new Martin Grand Performance yesterday. I really like the Siris back and sides and tonally it sounds like an in-between Rosewood and Mahogany. I originally bought a dreadnaught version but couldn't live with the one beaclaw slash which exteded half way across the top. I don't know how the guitar passed Martin's fussy QC. The Grand Performance body style is a lot sexier and easier to hold on the lap. To me it sounds similar to a dreadnaught AND a 000, giving you the best of both worlds. I also like the more contemporary pickguard, similar to a Taylor (a huge giant step for classic Martin styling). Also like the creme colored binding front and back which really classes it up. In my search for this acoustic and demoing multiple guitars, I've noticed something lately about Elixir coated type strings however. On the guitars that had em in the showroom, the ones with the coated strings really dulled and crapped up ebony and Micarta fretboards. I believe this is caused by the fingers rubbing the coating off on the fretboard. Anyone else run into this? I don't like them anyway, so I'll be using the SP's on this Martin.