Pros: Less pain, and no blindness.
Everything else remains - the extreme chakra requirements, bleeding, etc.
I don't think it gives you any new techniques. The 3 base ones are Amaterasu, Tsukuyomi, and Susano'o.
Your skill with these initial 3 techniques can vary, ie in Sasuke's case he has Blaze Release, Itachi has his HAX Tsukuyomi, and Madara has an unusually large Susano'o, and can perform a special Tsukuyomi called Mugen Tsukuyomi
The others are probably awakened through sheer luck - Kamui, Kotoamatsukami
And then there's the base Sharingan extra abilities - Izanagi (which now seemingly doesn't require Senju DNA), and Izanami
Edit: Like thunderthehybrid said, it allows you to read more of the Sage's tablet. Basically, the eyes are much closer to both the Sage's and Juubi's.