One fixed for some twenty years. One mechanical for some 18 years, especially if my bow gets out of tune with two week to go before the season starts. I might not have time to tune it. The expects will be busy at the time.
I found there are advantages of having both.

I am trying out the rage hypodermics. Didn't get a chance to kill anything last year with them but hopefully this year. But my tried and true broad head that I keep going back to are G5 montecs.

125 grain Anarchey fixed BH

HJ

i can see the benefit of having both.
i tried 2 different broadheads this year which both tout themselves to "fly like field points" which of course they didn't. my regular 2-3" group from 20 yards became a 4" group as the arrows seemed to plane off to the left on me.
presumably a mechanical has less impact due to wind and a truer flight in general. i'm considering getting some to find out for myself.

I like fixed, shot Muzzys for almost 20 years now and the RH Blackouts last year in addition to the Muzzys. I don't have to worry about whether or not the blades deploy with fixed. This doesn't happen a lot, but once is too many times in my opinion when shooting at an animal.