I'm running a custom 1 piece shaft from A&I Balancing which is a local drive line shop close to me. Snapped my 2 piece off at the carrier. So he took the OEM flanges and made a 1 piece from the left overs. Has yet to fail me yet.
I'll have to mention that to cci, I'd like to swap to a 1 piece when I swap my 4:30 gears from my reg cab to my ccsb, but that things gonna be moving on the highway with those gears.