I only hear justified praises of letsencrypt. Also thanks to the EFF and developers of certbot, which massively improved the toolchain around certificate deployment. Not the favorite activity for admins, but this made processes like certificate renewal/revokation much more convenient.

I think the portion of users that check a certificate after the browser treated it as secure is well smaller than 1%, probably well below 0.1%. And I guess these TLS connoisseurs have a positive inclination to letsencrypt as well.