I have a Progressive Industries EMS-PT30X This is the second season with it and so far I'm very pleased with it.
Prior to this I had a TRC 30AMP Surge Guard for 9 years. Never died just did not trust it any longer and towards the end it was not reactive to low voltage. I had to replace the plug on it once and it's a sealed unit that TRC will not touch. Tough separating it since it is screwed and sealed with silicone but once inside it was easy to replace the 30 amp cord and plug. The progressive unit would be much easier to service.
My vote is on the Progressive unit.