Perfect minimalist lights if you don't want something resembling a 6 cell Maglite bungied to your handlebars! =)
... Seriously though, these do a great job. Neat, small, stylish and very effective. Plenty of light to illuminate unlit cyclepaths on dark winter evenings in both constant light modes with decent spotlight patterns and good penetration (probably close to 50 yards visibility and will pick out reflective materials at over 100) Battery life seems very good, about 4 hours so far out of a single charge. Battery pack rubber/velcro mount doesn't look like it'll secure very well, but it does, staying put over some very uneven road surfaces (doubt it'd cope with Downhill MTB tho!)
Only downside is that the rubber bungie style front light mount means adjusting the beam position left/right is tricky to get right and doesn't always stay put, not so bad up/down but still not as good as the old cateye mounts these replaced.
Docked a star for that but otherwise, these would have been a pretty good buy at the full price