You can also see Jon's logo here, which is a very nice touch.
A shot at the end of the whistle, showing the last three holes. I also kept the foot of the whistle in the picture, so you could see the curvature I mentioned before. I think the slight curvature at the bell makes the whistle a little more comfortable for me to play when I drop my pinkie down.
Volume: Slighly above average volume. The first octave and the second octave are actually quite close to each other in volume, which is nice. Tt really doesn't get loud until the 2nd octave A and B. Mostly, the whistle plays a shade louder than an average cheapie like a Generation or Sweetone.
Responsiveness: Fast. This whistle can take everything I can dish out.
Tuning: Jon has mentioned to Dale Wisely of Chiff and Fipple that his whistles optimized for an octave and a sixth tuning range. I found this whistle in tune across the entire two octave range. The A and B require slightly more push in the first octave, and the second octave F# requires more push, too (which can make you want to overblow the G when you get up there). But these pushes are well within normal range that'd I'd expect when getting to know a new whistle. they aren't extreme or what I'd consider "breath gymnastics".
C-natural: OXXOOO plays a perfect C-Natural. For that matter, so does OXXOXX and OXXOOX. Take your pick! OXOOOO is about 20 cents sharp, but I only use that fingering when I'm flipping through a fast run on a reel, and I doubt it's that noticeable then.
Hole size and placement: The holes are fairly evenly spaced, and on the smaller side of average. Like most whistles, the E and F# are closer together, but not so close on this whistle that my finger's touch.
Air volume requirements: Low. I can get through 2 reps of an A part, and a full B part on one big lungful. This whistle is very easy to play in that department.
Air pressure requirements: Average. The whistle is pretty easy blowing in the second octave, going up in requirements as you go up the scale. The 2nd octave B only requires slightly more push than the Generation D I pulled out of my whistle drawer.
Clogging: I never really noticed that much clogging playing this whistle. I don't think I'd need to give it any kind of treatment.
Wind Resistance: Medium. It will take a fairly good wind, but if it cuts directly perpendicular to the wind channel, you're out of luck. But this definitely minimizes the amount of wind shifting you have to do out of doors.