I had 550 cc saline but since I went in for a tummy tuck I decided to get my saline boobs re-done with 800cc silicone. I am happy with the silicone. They look better and there is way less rippling. Was it worth redoing them?? Probably not...but if I had to chose between silicone and saline I would go with silicone.
Also, ( and this is important) if you like the way FAKE boobs look then get SALINE because silicone looks very natural. They are harder to push up and make look fake. I kind of miss that but now there is no rippling and they feel better so I guess its a trade off.