I prefer Satin Ice, I have used FondX and didn't like it much. I have seen Elite at my local bakery shop but have not tried yet. Taste wise, I don't have a preference to either, I don't like the taste of any fondant, so I'm not a good judge.
But people do compliment the MMF versus any other fondant brand. I hated making it at first because it was too much work and like many others I have two children, work full time, and am a full time student. So I didn't have the time to make it before.
But recently I made it using the Kitchen Aid, using Mayen's Tutorial from Way Beyond Cakes and found it much easier, I also added chocolate modeling clay as she does in her recipe on her Facebook page and it worked much better for me.
So I guess in my situation it's just going to depend on how much time I have. Everyone has different preferences, so just go with whatever works best for you.