You'll have to own one to know the difference...
but AFAIK, Oakleys are not of lifetime warranty... it is a
misconception by many people... Oakleys are only 1 year warranty
free and only if you keep their warranty card, stamped by an
authorized dealer and you'll have to keep your receipt on which
Oakley will do the repair with no questions asked. However if it is
more than a year, Oakley would still do the repair for a fee of
$30... but judging from the impact resistance of Oakley shades, wat
are the chances of it needing a repair...?? 
Currently wearing a Half Jacket, thinking of getting a
M-Frame(Hybrid S) and Juliet in the near future. Btw, their
prescription glasses are also great, esp. Wiretap... 
P.S: there's no point going around to compare the prices of
different shops... I think Oakley Singapore does very strict
control on the prices of their shades and glasses, so not much of a
difference.
