Serengeti
I have had a pair of the Serengeti Lamone with the non polarised Driver Lens. I work in the tropics and found them excellent under full sun and also good under low light conditions. The photochromatic lenses seemed to go light enough when the vis was marginal and dark enough when the sun was at full strength.
I consider myself to have sensitive eyes, hate being out in the sun without sunnies on. I will also mention that I am a VFR chopper pilot, so that may mean what is good for me may not be ideal for an IFR Jet Pilot! I have put a few scatches in my current pair (after a lot of drops - glass lenses are the best for scratch resistance) so am also in the market for a new pair. Am planning to stick with Serengeti though.
I would recommend the S-flex temples as a great option under a headseat - very low profile. I get a headache after half an hour if the temples are too thick under my David Clarks. I've worn my Lamones with the S-flex temples for 8 hours straight with no issues.
I have worn polarised lenses in the chopper with no issues (low tech cockpit helps!), but have heard one pilot say that he'd never wear polarised glasses in the low level environment because in makes it harder to see wires. Am tempted to try the gradient lens but don't know if i'll get too much light coming in through the bottom windows of the chopper - esp over water.
Think I'm going to go with the Saltos this time. Good Luck with your shopping...