I own or have owned a S&B PMII 5-25x56, Nightforce ATACR 4-16x42, Premier LT 3-15x50, USO LR-17 3.2-17x44, Bushnell 3-12 LRHS, Leupold Mk4 4-14x50 and some lesser offerings. March in Australia supplied me with a 5-40 for the 2017 season but life got busy and I only managed to use it three matches. I also did a brief T&E with the March 3-24x52. As far as glass is concerned March is excellent - As good as anything I've used bar perhaps the Premier LT, which is the best I've seen.
March Pro’s:
Compact & Lightweight given magnification ratios
Outstanding glass
Good if not great reticles - Usable across mag range
Illumination intensity well scaled and without bleed
Zero set design is simple and intuitive
Low profile turrets with tactile clicks
Cons
Parallax on 3-24 slightly less forgiving than competitors, not an issue with regular usage
Non-capped/lockable windage
Warranty - could be a deal breaker for some - though it's extremely rare to hear of anyone encountering problems with March
All said in my humble opinion March are absolutely a top tier optic, if the 5-40x56 came with Minox's MR4 or Kahles SKMR3 reticle I would probably have to buy one.
koshkin I believe has done some extensive testing with March and is probably the person best qualified to comment on them.
3-24x52
<a href="https://imgur.com/7e2OPyd"><img src="https://i.imgur.com/7e2OPyd.jpg" title="source: imgur.com" /></a>
Note the size relative to the Bushy 3-12x44
<a href="https://imgur.com/wmj4r7H"><img src="https://i.imgur.com/wmj4r7H.png" title="source: imgur.com" /></a>
5-40x56
<a href="https://imgur.com/t8AU6HU"><img src="https://i.imgur.com/t8AU6HU.jpg" title="source: imgur.com" /></a>