I can echo all of this - we also pay, we're very happy, the concurrency is nice (I believe they're bumping it to 80x soon - when my coworker asked "but what's the catch" I realised we pay by the CPU minute anyway so higher concurrency is a win for CircleCI -and- for US ;) ).

I've also hacked about the 'merge' problem but it's not entirely satisfying.

That all said, with GH actions currently being entirely free, and doing PRs better than CircleCI, we might shift our focus there.