Beanies-- too hot
Baseball hats-- bulky
Nothing-- too naked
Spyder Pilot ACS- Halo B hopper w/ rip drive, and a PMI 72ci 3000psi HPA tank. Haven't gotten around to modifying it nor getting the money for upgrades...
Covers what it needs to, comfy, cool.
If you have long hair, it can be difficult to get on.
Nice padding in the front, covers the back of your neck and keeps your hair out of the mask. Very cool looking and very comfortable. For the most part, it keeps the paint out of your hair, if you are prone to getting those pesky headshots.
The only bad thing is that for me (I have long hair), it can be kind of difficult to get on. Once you can get that, though, it's well worth the time.
I like the padding in the front, and it gives me an extra sense of protection.
Highly recommended, really makes the mask feel more comfortable. A+