I didn't even know there were different types of tubes! I have a spare tube, just a regular bontrager one that I carry around. I've not had a flat yet, but I have had to replace the tire itself when grotpeter trail took a chunk out of the sidewall of my rear tire. I got one with kevlar, hopefully I'll be able to ride these rocky trails for a while before having to replace it again, it was expensive!
vickie