It took me a little while to warm to the Camelbak bottles, the primary reason is that hardheadedness you mentioned. I just couldn't get used to the straw setup. I like the shape and the look, it was just that one thing that kept me from using them.

I thought I would try some of the 750mL bottles for wildland firefighting last season. No complaints... they held up like Nalgene bottles and I found I liked the sip feature more and more. I replaced the bite valves and straw but the old ones could have lasted another season but my OCD kicked in... The sip feature isn't perfect for all applications but when spill prevention is an issue they are very nice.