Let's Encrypt certificates only last for 90 days, so you either need software on the server to renew them or be prepared for a lot of admin. Someone who's actually used them may correct me on this...
Let's Encrypt is the least effort of any cert I've used. I would switch just for the convenience, forgetting price.
If you are on shared hosting with CPanel, renewal is automatic.
If you are running a dedicated *nix box or VPS, just install Webmin/Virtualmin and it will full automate certificate renewal.
Unless you need some higher level of extended verification, I can't imagine a reason for not using Let's Encrypt.... oh wait, one reason: you're on a Windows box. The tools there are improving though. But last I checked (a year ago or so), you still needed sysadmin skills to make it work on Windows Server 2012.