The Persol 714s are the best pair of sunglasses that I've run across so far. they are solidly constructed and seem to be extremely durable in-spite of the hinged construction that lets them fold up. The hinges are solid, well constructed and feel like they could easily see many years of use without wearing out. Which brings me to the next point - the folding design is just uber-cool! Both folded up and open, they look great and stylish, especially on formals  - the tortoise brown pattern is very classic which helps.
The lenses are excellent - coated on the inside to reduce glare and constructed out of glass rather than polycarbonate. The view through them is very sharp and contrasty and I don't notice any waves in the glass that cause optical distortions. I have the polarized brown lenses and for anyone on the fence about polarization, my advice is - go for it. The combination of brown and polarization really cuts through glare and makes everything look clear and contrasty - especially on sunny days. Side by side with my P3 Plus brown glass Ray Ban Tech sunglasses, the lenses on these are noticeably better.
In summary, these are an excellent pair of sunglasses and a pleasure to wear.
Subsequently, I managed to find the Steve McQueen PO 0714S 96/S3. These are constructed out of a less rigid plastic than the 24/57s that I reviewed earlier. The stems fold in, unlike the 25/57s and have a double arrow where the stems fold. The lenses are a gradient blue polar and are rated at 2P, so not as dark as the 24/57s which are a 3P. All in all, the 96/S3 is a very special frame and I'm going to enjoy wearing them on a nice suit.