When I go hunting, we take a 4x4 because you never know of the terrain or the weather. The ranch 4x4 is an older truck, not very pretty, but it gets the job done better than any pretty sedan.
I generally think of my rifles the same way. In fact, when I bought my own first rifle back in about 1988 or 89, it was a Browning Stainless Synthetic (called a Stainless Stalker) in, guess what, 7mm Rem Mag, and I remember even the catalog similarly marketed this rifle (which was essentially one of the first stainless synthetic rifles available) as the "4 wheel drive of rifles." Well, that got my attention, and as an 18 year old kid, it fit my then philosophy. Well, then again, to an extent, it still fits my philosophy. I would say that about 90 to 95% of all my rifles are stainless synthetic. Do I have some beautiful, pretty wood/blue rifles? Yes. Off the top of my head, a Tikka WH Deluxe in 7mm Rem Mag, and a Sako Deluxe in .308. These guns, especially the Sako, are just too pretty to take out into the field. However, with my stainless synthetic rifles, I don't worry about scratches, possible change of POI in extreme temperature changes, or greater possibility of the formation of rust.
Why do I say all of this? Well, when you mentioned that the sling is not pretty, I started smiling because that is exactly what I though when I first saw it. However, I must say that sling, other than looks, truly has all of the benefits that all hunters want. Also, I don't have to worry about it getting ruined in the rain like I would with a pretty leather sling.
For those who have used both the rubber sling and a leather sling (even the "best" leather sling), there really is little comparison in terms of performance because the rubber sling blows away any leather sling....except for looks (big deal.).
Trust me, you are going to be VERY happy with that sling. I bought 2 of them a few years back or so, and I no longer use any of my leather slings.
Zachary