I have bought more complete sets of Bach Cantatas in my time than is probably good for a man! I started with the Leusink Cycle that was included in the Brilliant Classics 'complete Bach' set and is now available as a separate purchase: I would strongly advise any Bach newbie to avoid that cycle like the plague. The performances seem, on occasion, to have been thrown together with little rehearsal and with no real regard to 'choir tone'. Some voices stand out like sore thumbs; worse, the entire set of boy trebles have a weird tendency to 'hoot' -a most disagreeable sound indeed!
I then bought the complete Gardiner set: Gardiner is a solid conductor who you can generally rely on for performances of excellent quality and with sound musicianship. There is usually, also, a good deal of musicological learning underpinning the performance practice used. I certainly preferred my Gardiner Cycle to the Leusink (which went in the bin)... but they weren't really very exciting performances. They were, frankly, a bit dull. But the packaging was spectacular, so... you know: you pays your money and makes your choices! [...]