I've used CircleCI quite a bit in the past; it was pretty good. Feels tough for them to compete with GHA though when you're getting GHA credits for free with your code hosting.

I used Travis rather longer ago, it was not great. Circle was a massive step forward. I don't know if they have improved it since but it only felt useful for very simplistic workflows, as soon as you needed anything complex (including any software that didn't come out of the box) you were in a really awkward place.