I use a combo of the cygolite expilion 400 and the minewt 600...I use both mostly because I need to be able to see ice on the road at night (although not really this year since there has basically not been a winter in minneapolis this year)...anyway...the 600 definitely lights up a bigger swath of road, but it is also bigger and heavier...both have multiple brightness modes, but I like the flashing mode on the 600 better...the 400's flash is a three strobe - pause pattern that I just don't care for...while the 600's is a constant on-off pattern...

Cheers,

Josh