I rode it twice last year.
Being an old railroad bad, the grade is minimal, so starting it at either end is acceptable. I've read where people say it's easier to go from Galax to Pulaski, but I really didn't feel a difference.
The surface is very well packed, but I wouldn't ride it on 23's.
Fairly smooth for the most part, but there is a lot of horse traffic around the Ivanhoe portion of the trail. Thanks to the horses, the trail can get kinda rough. Oh, and a word of warning: the horse riders absolutely hate cyclists. Be polite and yield to the horses, but don't let the riders yell at you.
Places to eat along the trail are pretty much non-existent. There are places to eat in Galax, a snackbar at Foster Falls, and a restaraunt in Draper. The place in Draper is nice, but kind of expensive. I'm not sure a sweaty cyclist would be appreciated. Your best bet is to bring plenty of snack with you.
Motels along the trail? None. There are some in Galax, but once you are on the trail there are none nearby. Most people that want to spend more than one day on the trail will camp in Foster Falls.
Here's a good brochure about the trail:
http://www.dcr.virginia.gov/state-pa...rivertrail.pdf
Feel free to shoot me a message if you have any other questions.