Two great hollowbody electric Guilds IMO. Played a mid-70s X-175 several times and wanted it bad. Then found one of the last Westerly built X-500s this year. They are quite similar in all ways. The most notable difference between those two was the vintage Guild pickups on the X-175. Superior jazz tones, plus a great, worn in and comfortable feel on that guitar.
They feel much the same, but have to say the 2001 X-500 is the best-playing big body electric I've ever tried. Effortless action. The acoustic volume on the X-500 is excellent too, louder than the X-175.
MD