Though I've not personally used SS, I have a friend that does, and her house just REAKS!! I never understand why she continues using it when it smells so bad. I really recommend using Feline Pine Pellets, but you have to switch it very gradually...that's the key. No, they won't use it if you just switch on over completely. It has a different smell, different texture. You have to start small and slow with it...but I TOTALLY recommend it. It's GREAT for odor, great on the budget, you can even use it in your compost pile! Also has a low dust factor.
But like I said, you have to switch SLOWLY, and it helps to have a scooper with wider holes. But it's WORTH IT.
Oh, another thing I forgot to mention...the friend of mine that uses SS has I think four cats, and maybe three boxes. Might be a factor...lol. I think the worse thing about the situation is the fact that one of them sits RIGHT NEXT TO the guest bathroom's toilet (and I mean, your leg touches it while you're on the toilet) and smells AWEFUL!! It's in the bathroom guests use the most often because it's right on the first floor and right by the dining room. BLECH!! Makes it difficult for me to go smelling that the whole time...I literally have to hold my breath!