I just added a new set of whistles to my collection!

I ordered them ten days ago from the Irish Whistle Shop. It’s a set of seven nickel-plated whistle bodies, one head and a plastic fipple. There is one body for each key between E (high) and B♭ (low). They were made by David O’Brien, serial number 773.
To give you an idea of how it sounds, here is the Song of the Garden played in the key of D (Source).
I love the sound, it’s very different than the sound I get from my Feadog whistle. The whistles require a little more breath and a lot more pressure. They have a wide bore and are very loud, especially in the second register.
On the Feadog, I have to blow the low E and the high B very softly to get a nice tone, but my new O’Brien in D will let me blow as hard as I want, all the way up to the high D. The Feadog has a breathy, lacking tone on the cross-fingered C♮. The same fingering on the O’Brien D sounds a lot better and it even has a thumb-hole for playing the C♮ perfectly. I play the recorder as well, so the thumb-hole is not a problem for me.
I tried the O’Brien whistle in all the keys I got. They all sound great except for the B♭, which is out of tune with itself harder to play in tune. I suspect I may be able to fix that by using the unusual ajustable window size (also known as embouchure size). Otherwise, The ajustable window size seems like a completely useless feature. Changing it by more than a few milimeters can make the whistle go out of tune or gives a horrible tone to either the first or the second register.
I highly recommend that you check out the Irish Whistle Shop and David O’Brien if you ever want to buy a good quality whistle from nice folks. Overall, my new instrument is now the favourite of my collection. But I am eagerly waiting for a Sindt whistle which is a lot more similar to the Feadog that I am used to playing, but, I believe, will have none of it’s flaws.
I’m editing this post to mention that, although I bought them second-hand, these whistles seem to have never been played before! I’ve owned them for less than a week and there are already large red marks around the finger holes where the nickel has rubbed off, letting the copper show. There was not even a hint of copper around any of the holes when I first received the whistles.