I love my Howard low D. I have a Chieftain high C which sounds nice but I find it needs a lot of extra pressure to reach the high notes compared to my pal's Sindt whistles. When I get around to buying a proper high D I'll get one of those. I've got a cheapo Generation which is ok for learning in the house but I wouldn't take it to a session (even after the necessary tweaking). But then I don't expect too much from it given that it's mass-produced and only cost about 3 quid.