Be careful with the Seven Slings. From what I understand, the fabric is really thin and may not be thick enough to be safe for a heavier baby or frequent washings. Just check your sling very often for wear & tear!
I have a Wrapsody stretch for Newbie, as well as a few ring slings, a WrapStar MT and another mama made MT, and a couple podegis. I don't particularly like anything that ties around my waist, so I don't have any SSCs (I tie MTs tibetan).