Bright beam and easy to change brightness. Clip is great to put onto belt loop.
Reliable and easy to carry around but make sure you have a lead or something so it is easier to find at night (that dreaded search for the light in the middle of the night!).
Intuitive to use and the battery is still going strong. Agree with @Vaddiszno - would be nicer to have a AA version for availability of battery and common to other camping equipment.