I have two friends that own 513's, I even got to borrow one for two months earlier this year. I agree, on paper it would seem like the perfect guitar - something that provides Strat tones, PRS tones and Les Paul tones, yet the reality is very different.
The single coil sounds good, but far from great. Way too smooth and to my ears they miss the clarity and the punch (although I would put a lot of this down to the Brazilian Rosewood neck and mahogany body combination). Heavy humbucking sounds very muddy. Only the open humbucking tones were to my ears - passable.
I must admit I love the feel of the neck and Brazilian Rosewood does command a price premium these days, but I doubt it will ever command huge premiums or add to the collectable aspects of these particular guitars. Far from it.
I agree with Niall, at the end of the day I would sooner a Strat and PRS (which I do own, so no probs there!). As I said to a friend of mine, one guitar that provides three tones that give you seven out of ten if you are willing to compromise is OK, however, I don't want to. I would sooner own three guitars tonally focussed on what they are good at and give me 10 out of 10. Anyway, if you have that amount of money to blow on a 513 spend it on a Tyler. It's a much, much better guitar.