just to have a booster with the extra SIP? My older daughter currently has an 85 that's used in harness mode, and I'm debating on "upgrading" to one with SICT. (She has a few more pounds to go in harness mode, but I'm thinking down the road here...) My youngest has an Advocate, and I love the air cushions. Yes, they are huge, but I just love knowing they're there.