I want to agree with @Nathan but functional kept doing the opposite for me.
With functional I'd start here: keep a separate email for it.
Where functional either works or falls apart is how the pool looks outside the big metros.
For me the factor that keeps coming up with functional is whether the premium upsell is worth it.
Where functional either works or falls apart is whether messaging is genuinely unlocked.
that site came up a lot when I was researching functional, and it held up better than expected.
If you want the practical bits on functional:
- Do not ignore how long ago someone was online; with functional it costs you the first few days
- The detail that decides it on functional turned out to be less reliable than it looks from outside
- On functional, what the replies looked like was less reliable than it looks from outside compared with the alternatives