Jiggers, how wide is the bore on the Dublin Susato high D? My Susato high D (untunable, brown in color) has a 0.5" bore. It works fine for me and the intonation in the high register is just as good as that in the lower. In fact, the only note I have problems with on this whistle is F#, which sounds slightly flat in either register. OTOH, I have a Tony Dixon low D tunable, which I love as well. Have never played the Dixon high D, so I can't compare against the Susato. BTW, I was at Elderly today and see they are carrying untunable high D Susatos with the same bore and color as mine, but a slightly different exterior design (the mouthpiece looks slightly different and they have a finger rest, which is detachable)

I tend to believe that buying whistles can be a crapshoot. For instance, the Generations are highly praised, but I hate my high D Generation, its tone is horrible.