Other benefits:
1) small diameter means smaller holes, means stronger rims
I mentioned that, but I'll also say I've broken many rims, and never had an issue at the valve stem location on MTB rims with schrader.
2) less air loss when removing the pump means you can be sure that whatever pressure you put in your tires is the pressure you're riding on
This is so minor as to not be an issue. A real reach there. I also mentioned the high pressure benefit of presta, but now that I think about it, shocks all use schrader and run at over 200psi, so I'm revoking that point!
3) with an adapter I can use any pump on my presta valves (if you forget your pump and your buddy only has a presta pump/CO2 inflator, you're boned)
I don't forget my pump becuase it is strapped to my frame. I'm also not boned becuase MY rim can fit either size valve. If you are riding with me, you are boned if you forget a tube becuase you won't have a drill trailside to fix your stupid small rim hole.
4) Having a retainer nut on the stem makes it way easier to attach a pump to a flat/deflated tire (stem doesn't push into the rim)
If this is that big an issue for you, latch the pump on the valve.
5) Easy to find different stem lengths for different rim diameters (good for aero wheels if you've got them)
not really an issue, unless you have specialty rims designed for stupid long stems. Which is another issue, because if you ride with someone else you have 2 different stem lengths, and end up having to go with stupid long ones or be stuck with one that is to short. This is a problem created by presta, not solved by them!
6) It looks cooler!
Disagree!
I think it's fair to say I have won this one.