Aftrmarket parts are made to the same specs and most likely come from the same factory . Nothing wrong with SEI or Sierra items
I don't agree with this at all. Some of both companies product has been Junk.
But to be fair, I haven't used anything from either of them for over 7 years.
Over my 30 years working for marina's I sold and installed a lot of Sierra stuff, some of it wasn't that bad. But you really had to look carefully before wasting your time installing it. About the only good thing I can say about them, they paid full flat rate at our posted hourly rate for all warranty repairs and they paid within a few days.
SEI on the other hand was terrible to deal with. They didn't pay any labor and it took a very long time to even get the part replaced. After that happened twice the only way we would use their parts was if the customer bought them and assumed all costs when something went wrong.