Xenon seems to be a little bit whiter/brighter than a standard bulb. Personally, I would skip the incandescent bulbs and at minimum throw in a MagLED drop-in.
Now, back to the MagLED and Malkoff drop in's.
The MagLED drop-in's I really liked because:
1) It is readily available, thus returnable if you have a problem.
2) Long run time.
3) More durable than incandescent bulb.
4) Decent throw and brightness.
5) Focusable.
6) Easy drop in.
The Malkoff drop-in's I really like because:
1) Well made and durable.
2) Decent run time, though much less than the MagLED.
3) Still focusable, but like jzmtl stated, it isn't flawless.
4) Very good throw and brightness.
5) Easy drop in.
Mike