Is it better to switch from scratch to Devise ?

Hi everyone,

I'm working on a project since some time now and made up some authentication system from scratch thanks to Michael Hartl among other resources... I was just thinking about the idea to use Devise instead, to make it even more powerful but I'm not sure that it would be so helpful.

Can somebody tell me what is the real power and use of Devise and what does it bring the most.

Thank you,
wishing you a great day