Browse around a bit in the Cool Fall subforum; you will find out more there than I can answer in a single post.
I would say that the Spy is around 3.25" long and on the highest level (as sent from Data) it drives the emitter at 1000 ma and should put out around 160 lumens... it seems to be a bit brighter than my Clicky 140CGT on burst.
Difference is that the Spy can run continuously at that level and it likely lasts over an hour. Pretty nice stuff.
The Spy 007 is an absolute work of art but don't let that stop you from using it if you pick one up. Work it hard and don't have any regrets.