Well, Painful or not? and how much pain? It all depends on one's pain tolerance, and one's pain tolerance depends on one's physical condition, body size and even age... I just happen to have very low pain tolerence... I was a ballet dancer, and I play a lot of sports, so my nerves are relatively more sensitive... I remember my second follow up was almost 3 monthes after my GRS, and I still asked Dr. Brassard for pain killer. (he didn't agree to give me) He told me normally people like athletes and dancers have more sensitive and active nerves, in another word, they have lower pain tolerence... and children are similar, actually normally the younger you're, the lower your pain tolerence would be...
Another factor is the body size (bone structure). I have a very small body size compared to white girls, so with the narrow pubic bone, the dilation would be more difficult, that could also cause more pain...
In short, painful or not, it's various for individials. Accordding to my own experience, I would say there are different types and degrees of pain on different stages... even now it's been almost 9 monthes after the GRS, sometimes I still experience some degree of pain during dilation or after some sexual activities... After all, it takes a good one year to get totally healed from GRS, and remember here we're not only talking about physical healed, but also becoming functional... It's just a long term procedure...
PS. Take a small example, it took me almost one year to feel totally no pain for my ear piercing... I don't know how long it took others?