Having 3 times the life of the normal seal sounds fine. With a Kubota engine that did more than 16,000 hours I replaced one pump once because the shaft and seal had worn. New pump is well under $169. I did replace a few impellers. The easiest way is to unbolt the pump, hold it in a vice and do all the tricky stuff there.

I bought mine from the UK manufacturer some years ago and when the newer version became available with the teflon plating I upgraded to that. At the time of the original purpose there was manufacturing fault with impellers and like a number of oter owners was chewing up and changing impellers every outing. The ease of the speedseal cover plate when changing impellers was a significant benefit. Highly recommended.