got my Lucido at the NEC after reading Grahams review as per Riks link above. One of the best bits of kit I've used for ages. Bit pricey, but very good.Not sure about the gnats though, I get bitten every time I go, always have done , even with a liberal splash of Jungle formula.
As Sedge says, batteries last for 'yonks' as all of the energy used is emitted as light rather than heat as per standard bulbs.