Here are some more pics showing the differences. The new board is the same length but a little fuller at the tip as you can see here, and virtually the same weight as the old. You may also see some of the small chips on my old board -- the new version is much more rugged and trouble free in that regard.
Here's a side by side comparison of how they look in the full down position under the boat:
I took the two boards out together with the Adventure and small sail, feeling that the lighter monohull would be more sensitive to any differences. After switching back and forth several times, the new board definitely had a better bite upwind with less leeway. It also slowed the heeling moment slightly -- not a factor with the AI, but a plus in the Adventure mode with gusts.
There are a couple of things it doesn't do as well though. The new board is a tad thinner than the old and with its ribbed top, also has less contact surface in the well (see below):
For those who pivot the board, with less friction in the well it is less inclined to hold its position. Likewise, when retracting the board part way, you have to use your knee against it to keep it jambed in place. The old board, a little narrower (front to rear), could be cocked back half way out. Having said this, I didn't experience any rattling in the well or other problems.
I think the new board is definitely a superior performer overall and have switched over to it. With all you fast sailors out there I need every advantage I can get!