I have used three iterations of the Kodak Readyload holder. The Polaroid is by far the best, most consistent, and least likely to allow light leaks in windy weather.
That said, Ready/Quick/Etc/Etc is FAR more expensive and much more restrictive than sheet film in a box. It makes much better sense to hold out for Acros in loose sheet form than to buy any film in the sleeve. I love to do without holders, love to write prosy notes on the sleeve, and love the convenience of switching in the field between two or three types of film, but if you shoot any volume, the price is prohibitive.