In summary

Use a portable/frame pump if you ...
- dislike paying for air
- are He-Man
- can show off a sweet matching frame pump
- ride on fat tires
- stop to help the helpless
- like criticizing those who use CO2.

use a CO2 if you ...
- ride when it's hot
- are weak
- are in an age appropriate triathlon
- have no mo room
- ride 23-25mm tires
- don't flat much
- know what you're doing
- are into firearms
- enjoy a bigger landfill
- need a good reason to keep riding when someone asks if you have a frame pump.