I had a Kuat Beta hanging rack and thought it was terrific... as long as I took precautions and didn't mind 15 minutes to load a bike. When a Saris Freedom tray rack was on CL for 1/2 price, I bought it. A lot less futzing with the bike, but it's much heavier than my original rack and I need tools to secure it. It did take much longer to load and secure the bikes on the hanging rack, but for me that was the only negative on the Kuat Beta. also, hanging racks are friendlier to fenders; you have to make sure your tray rack is (most are not), if your bikes have fenders (mine do).
My brake wire runs along the underside of my top tube and I didn't want it to scratch the bike on the hanging rack. So, I took an old wide inner tube, cut it to length of the exposed wire, and sliced it on the inside curve so it is now a sleeve between the wire and the top tube. Also, I bought the widest pipe insulation (I think it was 1 or 1 1/2" --get the one without the self glue) and cut that to length for the top tube and seat tube (the rack touched both) and slipped them over the inner tube/top tube. and seat tubes I found it was easier to just cover the entire tube, than make sure just the rack that touched the bikes were protected. I hang my bikes on one of those "above and below" storage racks at home, so if you want a picture, let me know, because I use the same protection there. (I haven't gotten pregnant yet, so I know that protection works! :) )
Sway was also an issue with the hanging rack, so I used two irish straps and put one from a lower tube to the end of he "arm" so bike wouldn't sway back, and another from a lower tube to the mast, so it wouldn't sway back. Another Irish strap to keep the front wheel from turning left and right and also to stop it from spinning. Finally another irish strap between the pedals, tube and back wheel to keep pedals and wheel from spinning. My bikes weren't going anywhere!
The saris Freedom is easier to load and work with, but it's heavier and takes up more room (doesn't fold), but it saves me loading time. It's not without it's issues for me, but I use my bike rack many times a month, so was happy to save the futzing time. Otherwise, I'd still be happy with my Kuat Beta, but still in the parking lot loading my bike. There are other Saris tray racks that look good and are fender friendly, if your bike has fenders. If you want to stick with a hanging rack, I do recommend the Kuat Beta (since sold on CL), along with my tips. Otherwise, the Saris freedom is good and there is another Saris model or two that look even better, as they grab the tires rather than the frame.
Roberta