Chieftain V3, V5, MK Pro, and Goldie Low D Whistles

I just got a V5 off eBay, so I thought I'd do a quick comparison between my low D whistles. Mike asked about the air efficiency of the whistles, so I did a quick test of playing the first octave G on each whistle for as long as I could hold it. Goldie: 27 seconds V5 : 23 seconds MK: 23 seconds V3: 19 seconds So the Goldie is the clear air efficiency winner. Interestingly, this V3 seems a tad flatter than the others, but I get what Phil Hardy was talking about when he says "fat sound". The tone is fuller than the V5, although at the cost of air efficiency and backpressure. I loaned my sister my first Chieftain V3, which was a bit newer than this one, and Phil Hardy personally checked it out for me, so I'm interested to get it back and see if there are any major differences between them, and if they are both slightly flatter than my others, or if my current one is a variant (I played it at a session and it sounded fine with everyone, so it's not too far off).