I don't believe in the 'best' rate.
In fact, I actively tell some prospect clients, that I do not want to be their broker if all they're looking for is the best rate or for the biggest cash back offer.
It's more important to look at what your 'true rate' is. That is, inclusive of all the fees.
And cash back - there's a reason why lenders are throwing money are you. After all, there's no such thing as a free lunch.
Watch out, as they'll get you hook, line and sinker.