The f'lite and f'liteII use the same design but the thickness is definitely thinner than the original oyster.
I have both the original and the two newer reincarnations. I would not hesitate to use any of them for the hard shell feature to protect content. Loving fine single malts and old world wine made them indispensable for my TATL trip.
I do not use the large or f'liteII 30 due to it is very easy to go over the 70lbs/434kgs allowance.
My original Oyster 28 is over 35 yrs old.