FC, your points are valid. My FIRST deer rifle was a 7 Rem Mag, w/the Steel tubed, ancient non coated/poorly coated scratched glass, Weaver K-4 ~ fixed 4x that came on it. I did get my first deer, a nice 8 point, but BARELY could see the reticle, a fine crosshair, but at 35 yds, it all worked out.
LATER, I just HAD to have a 3-9x, a Leupold, it worked fine, sold that rifle, got a 243 and moved it over. THEN decided it was just MORE than I wanted and I got tired of fiddling w/power ring. I decided 'less is more' - less shakes NOT using 9x on a sporter weight when away from a solid rest, and LESS to fool w/on the scope, just aim/steady/squeeze.
Sold the 3-9, and from then on that rifle wore a 6x36 M8 Leupold for the duration I had it, and I never found it wanting, shooting turtle heads for plinking/practice. It took deer, crows, rabbits, etc. you name it. That scope later went on a 270 MR and a 1B 270 and others, even getting a double on crows at a good bit over 300 paces w/1B Ruger.
No doubt, for some - a fixed power may not be best, it's all about THAT individual's eyesight, AND application.
I have and use both, but if I could only use one, for ME, I'd use a simple 4x or 6x, as that's what MOST of my deer rifles had when my deer dropped. Again, NEVER did I fail to kill, because I had a 4x or 6x on my rifle at the time an opportunity present.
