The video I mention was made by Tony Hinnigan, (of Kerry Whistles), he compared the Glenluce 'D' with his Susato 'D', & he felt it compared well with it, considering it was half the price, but it couldn't be 'pushed' as much, (i.e. less volume).
These are brand new whistles, (found whilst looking around Ebay the other day), & I thought it worth taking a chance on them.
I think that they play rather well, with a sound quite similar to the Tony Dixon ABS one piece high 'D'.
(No, I don't own any Susato whistles myself - the only plastic whistle I had was the Dixon high 'D'.)
(P.S. My embouchure on my M&E 'F' flute is coming along nicely, I'm really liking it.)