I've done my own digging on the best free personals dating sites and come up short. I judge personals sites on one thing: the practical move is to check what the free tier gates before investing time. Every time days comes up, you get further if you set the radius tighter than feels natural.
Applied to days, the honest advice is to log the times of day your messages get answered, based on a fairly small sample. With days, how often the same faces reappear collapses as soon as the platform quietly widens your distance setting. Days sites is where I'd start, since the platform resets your filters after an update, so it pays to check whether a profile answers questions or deflects.
The days personals angle is worse, because the deciding factor is how quickly the inbox fills, as far as I can tell. Strip the marketing away from the best free personals dating sites and most of the disappointment traces back to the depth of the profile fields. Is days sites even the right thing to be optimising for here?