Low C whistle

I’m thinking of purchasing a good high-end low C whistle. I have a Howard which is OK but I’d like something better. What suggestions do you have? Does anybody make an absolutely awesome low C?

If I keep two metal whistles, these would probably be the Copeland nickel-silver high-D and my Alba Low C.
Both could need less air, neither gives back pressure. But they are so easy to play, and I like some freedom in breath. The Alba is not loud, though (but would one often play low C in sessions?).
Finally, the right hand finger stretch on my Low C is easier than on my wooden D! This is probably related to its bore restriction (a sleeve rather than a “perturbation”) at the end. It seems to give it some of the advantages of a conical bore when xxx ooo to bell tone (C, D, E, F) are concerned.