My "guess so" wasn't meant to be rude or incredule. It was just that I never seem anything that would suggest reliability between both Slims were considerably different.
Both probably won't be as durable as a NES or Atari that you can still play fine nowadays, but considering industry standard they are very solid products.
Well cartridge based systems are always more durable then disk based systems because there are no moving parts and lenses. Well the original North American NES was somewhat flawed but on the plus side the controllers weren't directly attached to the console like on the original Japanese version.