Every Garmin I've tried has been a complete mess, laggy, and deeply unstable in its connection and what notifications it supported (if any), whether it was cheap or expensive.

I'd love an alternative, but from the models I've tried I don't think Garmin is anywhere near what I liked about Pebbles. Closer than some brands, but not anywhere near what I'd consider "close". Bangle.js is closer, for all its (many) flaws.