Mine is a good condition surplus flight suit from the local forces surplus store.
It is great, warm, has lots of pockets and knee-boards oand, with the gloves I always use may delay the effect of fire.
In any event it keeps all my key items together. I don't fly a PA28 or Cessna, but wouldn't be ashamed of wearing itin those types.
What you have to think of is not how it looks (who'd wear a Mr Blobby suit else) but what it does....
A flight suit won't help in a collision - nothing much would.