Anyone tried an MSD E Curve distributor?

I was going to buy a new MSD 6AL2 programmable to let me play with timing. My brother has one and I like the idea of it. I was all set to order it today when my carb guy says he uses the MSD E Curve distributor on his 340 and 360. Three wires, adjustable timing curves, and no need for an MSD box. If it works well, I could probably sell my Pro Billet distributor and MSD 6 box to pay for it. Does anyone have one? How well do they work? Are they as adjustable as it says? Any info would be great.