Slim,
To be truthful (sorry, Roashooter), the only thing I do like about the GSR is the stock.
When it came out, I thought it was neat & peachy keen.
Not long after, I was looking for a workhorse general purpose .308 in relatively compact dimensions as an ATV gun, and the GSR was initially looking pretty good.
Then I sat down & considered it from stem to stern & feature by feature.
The forward Scout scope would be left off. Having tried the concept on three different rifles, I decided it doesn't work well enough for me to use, and it would've added bulk & weight to the trim lines I wanted.
The working rifle I was searching for would be used largely for defensive purposes if needed (animal, not combatant), capable of good shot placement out to a hundred yards or so, and didn't need glass.
The GSR would have been used with iron sights only. I find my eyes now work, surprisingly, better with a U-notch rear than an aperture, so the existing sights were no benefit, to me.
The useless mounting rail would have been removed.
I intensely dislike a protruding box magazine at the natural balance point for hand carry on foot. Seriously, hugely, majorly.
I do not need or want a 10-rounder, if it's going to get in the way.
The GSR would not have been carried or used as a combat weapon, and "tactical" just doesn't apply here. No need or desire for high capacity or quick mag changes.
Between the scope & the 10-round magazine, the gun would have required a special scabbard to accommodate the height, would not have fit in the one I have where I have it for ready access.
A shorter flush-fitting magazine would have been an immense improvement, but having had such mags improperly seat (when I thought they were locked in) before, I don't want to risk one falling out someplace along the way & rendering the rifle a single-shot. (This does not imply a bad design on Ruger's part, I just don't entirely trust the things by pretty much ANY maker.

)
I wanted a fairly short rifle for use in cramped spaces.
The 16.5-inch barrel listed for the GSR, at first glance, looked good. But, that doesn't count the flash suppressor.
Since I don't see much need for a flash suppressor, and it actually adds length without sufficient return benefit to justify the trade-off (for ME), that was a minus instead of a plus.
Same general overall length as a regular barrel in a similar length in terms of transport space and handling, but with a slight loss of velocity in the 16.5-inch GSR barrel vs a regular 18-20 inch barrel, with the overall length of the GSR coming in only about 1.5 inches shorter than the rifle I ended up buying.
The bottom "metal" on the GSR is polymer, and while Ruger uses a good grade of polymer, I just don't want polymer there.
The stock, I do like.
The looks are great, it should be quite strong & resistent to temp & humidity changes that can affect zero, and the ability to adjust for length of pull is a definite plus.
After considering all that, I decided the gun wasn't practical FOR ME.
When Ruger brought out the Compact Magnum in .308, its 20-inch barrel gives me 3.5 inches more actual barrel/bore with corresponding slight velocity gain over the 16.5-inch GSR, an overall length that's 1.5 inches longer, semi-buckhorn sights that work better for my eyes, and steel bottom metal with fixed internal magazine.
The CM weighs 6.75 pounds out of the box, the GSR weighs 7 pounds out of the box. Glass would add more weight to the GSR, so would an additional five rounds on board as opposed to the five carried in the CM.
The Scout also costs a bit more than the CM, with additional features (as I've explained) that would be useless to me.
I will emphasize here that I mean NO criticism of Ruger in any of the above commentary.
The Scout is an interesting gun, well-made, and offers features that appeal sufficiently to others to sell quite well for Ruger.
Also NO criticism of anybody who likes the gun.
I get quite picky about certain guns for certain specific purposes in my hands, and the GSR just doesn't fit my needs as well as the CM.
This is also NOT an attempt to turn anybody away from the GSR, or to nudge anybody into the CM.
Fortunately, Ruger builds enough models to keep most of us happy.
And, I would not have gone into all this in addressing the original magazine question, but Slim asked.

Denis