How often do you guys use the Spa once it opens?

I used it quite a few times, but less due to its utility and more in the hope that I'd encounter new townie interactions there. That didn't so much happen. I've had limited interaction with two townies, and I've read that there's an event for another that I'm unlikely to unlock. The location of the spa + the location of its entrance on that screen + how long it takes to get from the foyer to the pool + the forced walk in the actual bath x 2 (because you have to do all that again to leave) + the amount of time you have to spend soaking means there's a high opportunity cost.

One of the townies you can encounter there in the winter, though, may add value to the location for some players.