I saw it in person at the DEMA booth and was impressed. Looks like the new housing mold has some alignment 'ridges' for all 4 locks. Basically according to the rep I spoke to, the upgrade is a new polycarbonate front...they drill for your control configuration, swap all your controls over to the new shell, discarding/replacing or repairing any that are showing signs of wear or corrosion, same as they would with a typical maintenance. Pretty sweet deal for the price, IMO. I think I may well take advantage of it, regardless of whether I think I might upgrade in the next year or two.
With 4 locks the small dome (that's what they had on the demo) could be drag-rotated if I tried hard enough, but any sensation of 'rocking' on the two pinned points was entirely gone. Which was always more psychological anyway, but I could definitely feel a much greater sense of trust...heck, this way if one or two locks didn't fully engage, as long as they weren't two next to one another, you'd be at worst back where you started from, so in that sense its a LOT of extra safety.