Options for a simple over-temperature cut-off?
bimetal is in my opinion the best for you because when it comes to approvals which can be the most expensive part of the product development cycle you are much better off Now the mechanical life isn't going to be a problem because the bimetals that I use in TO220 packages have lots of hysteresis built into them so they cycle slowly AND the bimetal only operates under abnormal and therefore unlikely conditions  THE bimetal is immune to RF fields unlike the chip so it gives less likelihood of having to re lay your PCB I have used and specified thousands of these over about 12 years and have not lost one  Also I cant remember replacing one in equipment that I have repaired IF you must use a PTC then beware of them shattering on excessive fault currents I have blown up two series connected 265Vac PTCs on 230Vac but didn't put this in my badbeetles website because at present it only covers ICs