Hi Recky
very interesting post here, and many interesting answers as usual.
I also own a 1982 D-25 that has got an arched back-keep in mind that well into the early Eighties Guild continued to build arched back D25- and I couldn't be happier with it.
It was my first Guild, bought on E-bay ,won it for an incredible price last year ($540) and I read a lot about the sonic features of the arched back and was very curious. When it arrived from the USA I was glad it was in fairly good shape, but it had very old and ultra light strings ( they must have been 0.8 or even thinner should they exist on earth) on, I strummed a chord and thought it was awful and volumeless. Of course I immediately changed the strings to Martin Sp 012-054 and ...booommm...I was blown away, I couldn't believe the projection this guitar had..the neck was very hard to play in the beginning because the guitar had been kept with the lighter strings for years, so I gave a little relief to the trussrod and after a couple of hours the guitar was playing incredibly, resonant ,lot of volume, big bass and medium tones and sparkling highs. I find the neck very comfortable as I got long fingers , the fretboard is wide enough to fingerpick at ease and when you strum it the chords are full. I find the arched back makes a great difference in sound.
After experimenting with various different strings I find perfect for my taste mounting Bronze strings on the D-25 , to give it a bit more "body" and to quieten the higher and brittle end of the sound spectrum that the mahogany produces.
I also own a rosewood D-50 that I love but have been through a lot of work with it(I posted some questions here last year about it asking advices ) because being a 1987 one it has a slimmer neck profile and smaller fretboard that aren't suitable for my hands, I absolutely love its rich tone tough, so different from the D-25, after months and months I seem to have find a set up that's not too much tiring for my hands( when I play solo or duo acoustic gigs I normally play for 3 hours..quite a long time if you're not comfortable with an instrument). I tried to find '70s and early eighties D-50 with bigger necks but even last summer visiting the USA they seemed nowhere to be seen..just sometimes on E-bay, the last chance for us here in Europe.
Anyway if you like it and need it for your recording job or playing pleasure go for an arched back D25 you won't be disappointed, remember you can find D-25s from the early eighties with arched back ( just like mine) ,maybe they're a bit cheaper than '70s models everyone is after.
By the way:it's about time you get the bug for Electric Guilds too, thye're still affordable and gorgeous!!!!