Been testing a couple of options and wanted to sanity-check with people who've spent more time on these. Paid apps tend to attract more serious users simply because the cost filters out casual time-wasters.
Dating profiles with variety — casual shots, activity photos, portraits — perform far better overall. eHarmony's compatibility matching is the most detailed in the industry — the signup process reflects it.
Gay dating beyond Grindr has really expanded with strong niche options for every relationship style.