to be honest there is very little difference between the two... here is a basic run-down

Cold Air Intake (CAI)

+/- takes air from within (or under) the right side fender, directly in front of the tire
+ the air is not near your engine bay...so therefor it is colder (duh)
+ cold = dense ... so in theory your pulling in more air
- longer piping = harder to install
- (depending on rain in your area) you can suck in water and hydrolock your engine ... that's bad
- more expensive

Short Ram Intake (SRI)

+ can utilize larger piping (whale penis style) so can bring in lots of air
+ easier to install than CAI
+ cheaper (sufficiently)
+ no threat of hydrolocking your engine
- doesn't look as cool IMO
- using hot air, so the air is less dense/ herego, less air

i think i pretty much summed it up...but to be honest...there is very very little difference between the two...it is such a miniscule piece of your engine that it's basically not going to matter which you choose, it all comes down to where you live...

I have a CAI, but it's because i live in So-Cal and we get about 2" of rain a year...so to me it's worth it

hope this helped