I think having the fast rope option would be cool to have in the game. Having said that it isn't a great way to put people in an LZ. It is a very limited use tool that only a small portion of the customers on a helo will be able to use.
First/best infil option is almost always going to be airland. Minimum amount of time in the WEZ is best for all involved. Until the team reconstitutes on the ground outside of the helo they aren't an effective fighting force.
Next option is normally a rappel because it can safely be done from both sides of the helo simultaneously. Also, the descent is controlled rather than a free fall.
Next is the fast rope- some problems with the fast rope- it takes time to get folks to the door, on the rope, down the rope, recover. It also takes the gunner off the side the rope is set up on so your ability to return/suppress is limited at best. 30 seconds in a hover with no coverage on one side of a helo is a really long time. And if you take fire from that side the pilot is going to pedal turn the bird to put the manned gun in the fight which is probably going to knock down/destabilize whoever hasn't left the helo and if the bird doesn't turn exactly about the point where the FR touches your probably going to end up with a leg injury for whoever was on the rope.
Another thought about FR: Most of this sort of operation happens at night. I have seen more NVG's destroyed through FR accidents than from anything else. On the ground at night with no NVG's is really baaad. Oh yeah, with the HH-60 cabin space is at a premium and a 60 foot fast rope takes up a ton of room wheras a 100 foot rappel bag is pretty small.
Another thought about the time it takes to get out with a FR- You can only have one guy on the rope at a time because you can't stop once you start down and if the preceding guy falls or gets hurt you are going to make things worse by dropping another dude on him. So it takes a fair amount of time to get peeps out this way. I would guess at least 5 seconds a body if everything goes right.
My thoughts on fastroping are based on my experiences with the Pavehawk although I am pretty sure that they apply to the UH-60, -53, and cough, cough even the CV-22.
Still, it would be fun to have in the game...