Anyone been carrying/using either of these for a while? Found any negatives?? I'm thinking that one would be a pretty much perfect light, what with the magnet, swivel head etc,....I'd want a belt pouch for it, trying to work out which cell version to get, I'm thinking the R2 because if that 3.7 cell goes dead whilst I'm out, an AA will do. But the CR123 version is shorter, more likely to stay stuck to a magnetic surface etc??