that is fairly bad pyramiding. the pyramiding is due to diet... in their natural habitat it would take them about 80 years to grow the size that they do in about 15 (this is all generalizations) and because of that there are slight deformations. the shell is naturally supposed to be pretty much smooth all around. hope this helps!
Yeah it's not necessarily that the shell itself makes the tortoise unhealthy (i am pretty sure) but it's a sign that he was being fed the wrong diet. also, pyramiding can be reversed after they start to be fed the correct diet i am pretty sure (this will obviously not happen over night!). did you rescue one or what?
Adopted a rescue. I have experience with water turtles, california desert tortoises, and galapagos tortoises. None had "pyramiding". Almost all of the full grown Sulcatas I have seen seem to have it though =(
unfortunately yeah a lot seem to i think mainly because they are hard to care for and people get them not knowing what they are doing. that is great that you adopted one though. i raised two (one is pretty much fully grown (at about age 15) and the other is getting there). they don't have too bad of pyramiding... I just checked to see if I had any photos of their shells but I couldn't find any (there are some photos of my bigger one up at: http://www.flickr.com/photos/hazyskyline/tags/sammy/). This community seems to be fairly dead or I would have posted this hilarious video of my smaller one trying to have sex with my water pipe (and you can kinda see his shell in this video): http://smg.photobucket.com/albums/v201/coldskyline/?action=view¤t=0830081713.flv anyway, that one has slight damage to his shell (not from pyramiding but from damage when he was younger from other tortoises). hope something in this long comment was of interest/help! good luck with the tortoise!