No baby mommas or daddies in this forum I see. I used to use a rush 24 but I packed to much stuff. From a one day excursion to visit the in laws we used 5-6 diapers and about 4-6 bottles. With a extra clothes and a blanket I went with the smaller rush 12. I didn't go with the sling bags because I would be carrying the bag and the car seat and I found that mesaanger bags for me tend to swing to the front and can be kind of uncomfortable. YMMV.