It really depends on which key you are talking about, since there are so many bodies for that one head. I’d say that the lower keys are suited for one who is a soft blower.
I got a set of Syn whistles on monday, with bodies for D, C, B, and Bb. I liked the C and B the best, but I thought all were fantastic. Yes, the D does require some push to switch octaves, but the Bb takes a very light breath, with very easy octave transitions.
I was surprised by how good these were, and I wish I knew about them a long time ago. They sound very nice, are responsive, and just play very well.
Something to keep in mind though, is that if you have a very specific type of playability you like (hard/easy), that these whistles span a pretty large range of playability, as they are made from soprano Eb, all the way to alto A on the same head!
I am ordering the Eb and A now, just to see if those are beyond the boundaries for that bore size, or not. The D was perfectly playable, but yes, requires a push. The Bb did have a bit touchy of a low end and requires a lighter breath, but I’ve played touchier whistles, and actually I like the way the Bb plays. I don’t consider this a good or bad thing, it’s just how it plays.
C and B were right in the sweet spot in the middle, but I found all of the keys I recieved to be very good! I’d recommend them!
And yes, they sound fantastic! Can’t really say anything bad about them. But- If you are strongly opposed to whistles that must be blown lightly, or strongly opposd to whistles which need a hard push, I’d recommend keeping this in mind when you decide which keys to buy.