Spectrum guitar with Skyway trem...that's my next Alembic project. I'm currently searching my coat pockets and turning over all the couch cushions looking for spare change to fund it.
She's going to be a mini version of Royale, my Europa 5-string bass and will be called Regal.
As for the PRS 513 model - we sold a few of them (some with Brazilian rosewood necks) at the guitar store where I work part time. The players who bought them liked them - at least we never heard any complaints. They praised the tonal versatility and ease of use. I played a few of them but never found one that I liked well enough to take home. They have a unique tone due to the pickups - more focused and precise than a typical PRS. And the PRS trem system is real nice.
I'm going to guess that a Spectrum with a trem would be real close tonally and even more versatile. Plus, the neck-through design should yield more clarity and sustain.