Andrea,
I'm a big fan of pork spare ribs, and even pick up the boneless ("country style") from time to time. If you ask me, the only thing baby backs have going for them is tenderness. I think spares have a lot more flavor.

As to the membrane on the ribs, try using a flat-head screwdriver to lift up a little "tab" of the membrane from the top of one of the bones. Then, take a paper towel and grab the tab of membrane with it and pull down the length of the rack. I'm usually able to get all or most of the membrane off in one or two long strips.

Hank