What BriannaFL described matches my experience of free online dating sites almost exactly.
If you only test one thing on free online dating sites, make it what the real cost is after the trial.
I logged into the site at different times of day to get a read on whether the sorting can be trusted.
Unless you are in a major metro, expect whether the free version is a demo or a product to be the limiting factor on the site.
I would judge the service on what the subscription actually unlocks rather than on the feature list.