As always the March conversation gets hijack on theory and hypotheticals. As a long time user of both the 42 and 52mm in both hunting and target situations, I would make the following points based on real world experience and testing and re-testing Internet "facts".
1. In a hunting situation, using normal magnification ranges of between 6 and 10 power, both March models are superb at what they do. The lens quality gives extra definition to the target animal and removes many of the glare problems encountered in other brands.
2. Eyebox is not an issue if you know what you are doing, have set up your scope properly, and practice.
3. At 24 power, there is a need to focus any high range scope. If you are shooting at over 20 power at a live target then you need to offer the game the courtesy of getting things right for a clean kill (see point 2). This includes focussing properly.
4. With the Xmas Tree reticle, I found that it has a fantastic optical sweet spot at 17 power.
5. For weight to magnification ratio, on a hunting rifle, the 42mm is a go to.
6. And if you want a bit simpler, the SFP models are more than adequate.
But in the end it all comes down to brand loyalty and personal preference.
Theory and hypotherticals? I tested 2.5-25x42, 2x 3-24x42, 2.5-25x52, 3-24x52, 5-40x56, 1-8x24 and 1-8x24 Shorty March scopes. Which part of that hands on experience exactly do you call theory and hypotheticals?
At the end of all that, I liked the 3-24x42 enough to buy it and use it for several years, until the TT315M came about and I switched to that as my general purpose precision scope for several reason that I have carefully outlined multiple times.
You may disagree with my choices since, of course, they are personal (that is why I take the time to explain my reasoning when it comes to choices), but calling them "theory and hypotheticals" is pure and unadulterated BS.
As far as brand loyalty goes, that is where you may want to look in the mirror. I do not have a whole lot of brand loyalty if any. Now, there are a few brands out there I distinctly dislike, but as far as loyalty goes, I do not really have any. If anything, March is one of the brands I happen to really like since they kinda speak to my engineering sensibilities, although you are testing that a little right now.
At the moment, I own scopes and sights from SWFA, Burris, TT, Vortex, Delta, Bushnell, HiLux, Shield, Sightron, Elcan and MTC and like them all for different reasons. I have owned products from just about every brand imaginable in the past and I sorta have a habit to speak from experience.
Somehow I missed the memo that March is such a special brand that your take on their products is factual, but everyone else's is purely hypothetical.
ILya