Not first fruiting, but first big fruiting. I don't get the impression that they're any less abundant in edible flesh than Ed Johnston's trees, which have been big producers for many years. But there's no evidence to support my hunch, unless Ed has done this test himself. I've been eating Ed's durians for several years now, and will ask him about this.
Talked with Ed today. He has never done the percentage test with any of his three trees, D-123, Chanee and D-132, so I encouraged him to do it next years. He did say that these cultivars came to him in 1992 from Alan Carle of Australia, and that my trees are clones of his. He also said that a couple of folks who have been buying his D-123 fruit this year say it's the best durian they've ever had, and they've sampled extensively from SE Asian offerings.