I've never had to pump the primer on my 405 more than twice... I almost never have to prime it at all. I've heard many stories of the mag's NOT autopriming, and requiring water to be *poured down the intake tube*. Personally, I'm glad to have the option to prime it manually. BTW, CWO - you say the magnum is the 'stick shift of filters', yet it is the *automatic* feature that is often so touted.
All in all, most everyone likes the filter they have best - that is why they have it.
All in all, most everyone likes the filter they have best - that is why they have it.