I must agree with Mr. Horse about the D'Addario strings, especially on a new Guild.
I fought and fought with my D55 (new 2008 Tacoma) before I finally brought it to a Guild authorized luthier who set it up properly...and changed the strings. Still not as easy a play as my GAD or Gibson J-30, but her sound makes up for it. I think that GHS Bright Bronze are the ticket for this rosewood dread, and your fingers will thank you.
Never realized how much tension the D'Addario mediums had until I put a set on my Gibson...whoa! Bridge Cables! Yup, sound great but nearly unplayable. Now, that may be part of the sound, but I think you must get back to the compromise of playability v sound.
All that said, tried three D-50's at Music Emporium yesterday...well, two really. 197x-something ($1700), nice shape, kinda eh-sounding, wonder if it has a neck reset in its future...another looked like it had worked for a living, or perhaps was dragged behind a pickup truck! Passed on that...then they broke out the 1966 D-50 Brazilian. Looks like it shoudl have been one of my guitars, a pristine edge-of-the-bed guitar. Amazingly it had the signs of an expert neck reset, perfect job. Played wonderfully, with a much thinner neck not unlike my Gibson. Only played it fingerstyle, very very nice...but she didn't speak to me more than what I have at home...not worth losing my bed for $4800...
I still wonder about that one above listed at MF...