Jim,
I don't think they do. Reason being is that you can usually squeeze an extra .5 fps or so out of a motor drive with the Energizer e^2's... With my MD-12, it sounds like my FM2n is doing somewhere between 3.7 fps and 4 fps, instead of the 3.2-3.5 fps that's stock. The AF is also snappier in my F4s, compared to normal. It's also useable if said F4s is downgraded to a basic F4 with the MB-20, whereas, with the alkaline AA's, it can get painfully slow.
With respect to Nikon not recommending them, they didn't have enough evidence @ the time, since the original red/gold Energizer lithiums came out around the time the N90 did, so most earlier bodies were untested. In my experience, all my F3's have been fine on the e^2 lithiums, my N8008 was fine, and, of course, every F4 and F5 I've owned has been fine with them. Meters were always accurate. The motor drives also seemed to always have a little extra power, compared to alkalines.
Lithiums aren't cheap, but they do last a long time. They do, however have the sudden death issue mentioned in the previous post. They either work, or they don't.
-J