I think that 2 under 2 is going to be difficult at moments regardless of your age.
It also has its rewards, my boys are really close which is wonderful to witness.
As for the first being an angel I've found that it's more about ages and stages. Lately my troublesome one has been my elder son but at other times I've felt that he was the easy/angelic one and his little brother was a handful.
They do have very differant temprements but both of them bring thier own challenges and rewards.