I recall that TLC_31 has said that he had to discontinue Gilenya due to cardiac side effects. I can't recall anyone else here (of the regulars) who has tried it.
Try searching the forum using Gilenya as keyword, to read past posts about it.
If you're on Facebook, search for the private group Gilenya. I joined it recently, and the Tysabri group too, as I'm facing the same decision you are, Candy.