Just got my SCAB a couple of weeks ago. I have two boys, 10 and 12, and they have LOADS of room in the SCAB, even with my seat pretty far back (I'm 6'2"). I also would rarely carry adults, except maybe on bike race trips or to lunch, but I think it will be comfortable enough as long as I'm not driving cross country. Plus, I can easily roll any of my bikes into the back with the seat folded up. I honestly like the look of both of them, and there is no doubt that an adult, or two consenting adults, would have more wiggling around room in a SCREW, but the SCAB is perfect for me. One of the biggest reasons, is that I can fit it in my garage with a 7' tall, 8" wide garage door, and still have room to slide (barely) in front of the truck between the wall and the bumper. No way whatsoever with a SCREW would I be able to even get it in the garage.