i have never had problems with my 16g cartridges for mtb or road applications...i have seen a few people tear a valve off with a frame pump...and even when they work, they grin up at everyone waiting for them while they pump, sheepishly smiling while everyone waits, most people take me up on my offer to co2 it for them...
as others have mentioned better tires make this easier to handle, but i carry 2 tubes and 3 carts and it has always worked out for me, and i get complimented for short tube repair times.
