This is a good recommendation in my opinion. The size difference between most pen lights and the D25A2 Mini (as well as the FourSevens Mini M2A 2xAA) is almost negligible, and you get way better runtimes.
If it's strictly a 2xAAA penlight that the OP's after, then the Preon XP-G2 is probably the brightest. Maybe not the best, though. But that last point is subjective.