Originally Posted by
timcupery
I'm not sure what you mean by high or low profile,
Shimano has "Shadow" series deraillers for XTR and XT. They have a lower profile than the standard deraillers to keep them from getting caught on stuff during trail riding. I've read that the shifting performance is slightly worse than with a standard profile derailler though (never used one myself). For a touring bike, I don't think the Shadow derailler offers much of a benefit especially given the extra cost usually associated with them.
XTR Shadow:
http://www.speedgoat.com/product.asp...t=33&brand=226 ($280 vs. ~$200 for normal XTR)
XT Shadow:
http://www.speedgoat.com/product.asp...t=33&brand=226 (not a huge price difference here though)