I keep thinking about buying the 13's for my SJ-200. I have been a long time user of the D'Adarrio EXP Coated Mediums...they have good tone, don't break on me and last a long time. Lately, I have been playing with the LaBella Silk and Steel Medium 12's and have really like the way they sound. The LaBella's aren't lasting like the D'Addarios but have a nice tone.
I may break down and grab a pack of the Spectrum 13's before too long...maybe after I get my $100 tax refund.