Rick,
I was running XM 10k's and had one burn out last weekend. Bulbs were only 6 months old, I did notice before it went out that it was burning yellow instead of it's usual white.
I have heard good things about the Reeflux and also the new Coral Vue 14k's. I saw several pairs of the Coral Vue 14k burning this week at a friends shop. The color was very white and crispy.
I had already placed an order for new bulbs when I saw these in action. I replaced my XM's with Ushio 10K's, and so far I like the color, and after 2 days I noticed my corals were showing better coloration. I think in my tank the XM's were giving my corals a sun tan.
Weird thing about the Ushio's I saw was they are shorter than most SE bulbs. I also had to re-orient my sockets to get the nipple on the bulb in a 12 o'clock position.
I havn't checked Sanjay's lighting website in a while but it is definately worth looking at if you are considering a bulb swap.
I talked with Jay at Premium Aquatics at length about bulbs and the goals of my tank before I ordered the Ushios .
Kevin