Well, if you go with a small reflector, the light will be small, and put out a lot of useable light for close up, and will be usefull, but perhaps not all that much punch or wow factor.
Use a mag reflector or something, and you got a powerfull light! I guess it depends on if you already have a monster light or not. I'd go with the brightest reflector (throw) possible and just stick to normal lux's for up close (small reflectors) work.
Plus with a bigger reflector, you get a bigger host to have longer runtime! 6 NiMH does very well. Whoops up on 6 AA alkalines. My 5w green is still going strong at the same drive level after 20mins runtime!!