Just got them in today and checked them in AA MiniMags with rechargeable batteries. The beams of the NexStar (Xe), RS Kr, and stock bulb sure look different in brightness. The NexStar is, if anything, more of an improvement over the Kr than the Kr is over the stock bulb. It draws the same current as the Kr bulb (400-450mA).
'course, that's looking at the beams on a wall, which shows up the difference in color temperature clearly. Bouncing it off the ceiling and looking at the floor, the Xe/Kr difference is barely noticeable. Even less so with the AAA MiniMag. It's hard to compare the AAA and the AA. The AA looks brighter regardless which has the Kr and which the Xe.
Measuring shows 2.40V in the AAA, 2.45 in the AA, which looks insignificant, but I'd swear the Xenon NexStar looks whiter, if not brighter.
Here's a photo where I "clipped" the Kr to the Xe which was in the AAA MiniMag, then put a black divider between the two. I have to admit, right there they looked about the same to me, and the camera agrees as far as I can tell. The median value in the original graphic is Kr-25 and Xe-30, but looking just above the bulb I get 27 and 28. So, if the Xe is brighter, it ain't by much. Doesn't even look whiter here.