I don't own a McCarty 594 SC, but I do own a 2011 'Stripped '58' SC. I also own a pretty nice 2012 Les Paul Trad Pro.
Hopefully being totally objective here (noting that I play seated 95% of the time)... the LP is nice enough, but it also sort of tends to feel like it's just sitting there, somewhat heavily, too, in my lap, and not quite as much a 'part' of me. Balanced... OK. (Also somehow not quite as 'alive' feeling. IMO.)
The PRS SC '58 (which I bought afterwards) is pretty much the opposite in that it feels a 'friendlier' somehow, more ergonomic on some level. Balanced more like it's a real part of me. (IOW, a PRS!)
Oh, yeah... the PRS 58/07 pickups definitely sound a lot better than the Gibson '57s, too. My 58/07s were modded to split and their split-coil also sounds much better than the LP Trad Pro's split sound. (Yes, the LP will be being sold one of these days soon, especially after I also got one of the phenomenal Eastman SB 59/v's in their violin varnish finish, loaded with Duncan Antiquities. WOW.)
In comparing my SC '58 instead here... would anyone care to comment on how (or if) that guitar might differ much, if any, from the current McCarty 594 SC guitars, in balance/ergonomics?