Originally Posted by pony express
I would rather replace my 300 surge than my twenty thousand dollar trailer
Any protector that fails means either trailer appliances are also damaged. Or each appliance protected itself from something so tiny that it only destroyed a grossly undersized protector.
Each discussed protector is only sufficient when properly designed; when it does not fail. How to avert that failure? Spec numbers.
Some protectors do absolutely nothing for a different anomaly. No protector addreses all problematic anomalies.
A term SP is always misleading since it does not say, with numbers, which anomaly. Surge is a vague term promoted mostly by advertising to create confusion; that increases sales. Numerous and completely different anomalies are called surges.
Personal preferences are useless unless tempered by hard facts with numbers. An example: unacceptable voltage variations are obvious when intensity of a 120 volt
incandescent bulb varies. w4drr has provided another hard fact.