I've owned this whistle for nearly a year now. It has a nice tone and looks good. My only complaint is that the C sharp is flat unless blown harder than I'd like, and the top end B is noticeably sharp unless I shade it with my finger. However, Phil Hardy (the maker) actually reached out to me to offer to fix the whistle, and I plan to send it to him soon.
There are other whistles out there that are better (Goldie and MK are on my wish list) but they are hand made and more expensive. I might have bought an MK Kelpie low D if I'd known about it, but to give this whistle only one star is not fair, in my opinion. It's a good whistle.
Update: Whistle is back. The C# does seem to be improved. The whistle was polished up. The top end does is still a little touchy about how it's blown. Sometimes it seems sharp, other times it seems okay. Still not perfect, but serviceable. I did get an MK pro low D. I find it to be similar to the Chieftain, but the tone is more powerful and crisper, while the Chieftain is a softer whistle (both in volume and tone). The Chieftain is much breathier. The MK's tone reminds me of dry leaves, while the Chieftain evokes more of a wind whistling through caves type of feel, if that helps at all.
I take the Chieftain to school and play it in the stairwell, where it sounds great still. The MK was too loud. The MK would be a great session whistle due to its volume, but the top end gets harsh around the A and B, although in tune. Tuning seems better on the MK.