I don't think the "system" brand is as important as the type of filtration (material, microns, etc.). And that choice depends on what you want to achieve, i.e. remove debris, improve taste, prevent water borne parasites, etc. Most campgrounds these days have adequate quality water supplies, regulated and inspected like any small municipal water system, and typically chlorinated for bacterial prevention. However, in some areas there may still be a risk of diseases like crypto or giarda that may warrant some extra care if you are doubtful of the campground supply. If not that, you may want a charcoal or similar filter media that removes odd tastes or whatever you dislike.
Here in the eastern US, I just use a basic sand filter in a "whole house" system to remove debris.