Got an Alpkit Gamma for Christmas
First impressions:
+looks and feels nicely built
+the straps are easily removed for mounting on a bicycle helmet
+max output is good enough for cycling on unlit roads, lower levels are fine for walking
+the lower power leds have quite a bit of flood, good for reading or work closeby
+the higher power led has a sharp beam shape, focusing the light only where you need it, if the light was floody with the same total output it wouldn't be sufficient for cycling I think
-rear red light is rather weak (plastic ribbed strip illuminated from one side), don't think it's sufficient as single rear light when cycling (will test though), still a nice extra though and certainly won't blind anyone behind you