Schubert, I too place his cantatas at the pinnacle. What Bach did with his cantatas, especially the Leipzig work, is just superhuman. 54 cantatas a year for 3 years, in addition to his other duties as cantor. He wrote at least one new cantata a week on Monday and Tuesday, practiced with the choir the remainder of the week. How is that even possible? They are not formulaic tripe. They are masterworks. And lets not forget his choral preludes, cranked out at the same pace. The man was a gift from God, pure and simple. All this, while being a husband and father to double digit children, not to mention his teaching duties, and the constant frustrations of dealing with the blockheaded pietistic clergy in Liepzig, who regarded him as nothing but a third rate composer.
Can't wait to hear your thoughts on the Sigs! I think you have probably made a great choice.