PLA is water resistant so far i know,

It is true when you have hot water that it might bend if hot enough,

ABS is simple more impact resistant and can get more heat till bending,
As strong goes i did a stretch test a while ago on a machine and they were both VERY simulair, Not even worth to mention it,


I personaly also like the XT series and PLA/pha from Colorfabb, i am testing them right now and i am fairly suprised about there quality

Never tryed Nylon or Poly carbonate, but they are harder to get on your build plate and they warp quiet a bit so far i've heard, and you would need a full metal hotend to get your temps right. (Well you could do nylon on a Jhead perhaps, i've done my Jhead on max 245c so far.)