I don't know any particular facts about Leaf or Phase, but I agree the Leaf to me had a nice interface and Leaf always had an exceptional film like look.
If it wasn't for the lc10 (which was eventually fixed) I would have kept my Aptus forever, but my schedule meant my workflow had to be improved.
If I was buying a back I would go with Leaf, but I wanted a Leica, though I can still process out an older Leaf file and am amazed at how pretty it is.
Sometimes you say some things that floor me.
Leaf was always the 'photographer's' digital back, and I would be surprised if Phase didn't use Leaf's knowledge of Dalsa and color to improve all of the products.
Once again I don't know the particular facts about any camera company, but I do know that I like the people at Leaf a lot. They really cared about their product, never acted smug, but had great pride in what they produced. They also were one of those companies that wrote their own music, didn't do cover band, and stood behind their equipment.