In reply to Alpenglow:
I have Comici, Beta and some older ME pants (>10yrs) and none have them have gone at the crotch. However, as you can tell, ME fits me very well so I've not had any crotch issues.
The only "pant" that I've had a crotch failure is a pair of Backcountry Guide Pants from Patagucci. I repaired them with some delightful pink cotton which was all I had and they have held up fine ever since.
I agree with a previous poster, if the crotch sits too low, this is where they will split. My most common failure is holes in the arse due to too much sitting around bouldering/belaying at the top of gritstone crags.