Personally I prefer the Selway limbsaver. Interestingly I know two bowyers who greatly prefer one with two cups. They tell me the bow was designed for tension on the tips. One makes his limb tips slightly longer with this in mind.
First and foremost, use a stringer. Second, use one that is SAFE. If you are in danger of the tip comming out of the pocket, it isn't safe. Hummingbird used to sell one that allowed you to use the step through method without damaging the bow. I've used it and can't get used to it, but safety was the driver.