The Let's Encrypt initiative is really great and certainly they are making the web a safer place. The only limitation is that certificates are just Domain Validated not above them.

The adoption rate is high due to support from the sponsors and web hosting providers.

The implementation of Let's Encrypt was also easy, the auto renew process and not having to reissue and reconfigure it again on your domains takes a lot of hassle away. At Cloudways we have recently added it and response from clients has been superb.