4th, I've always had good results from the Chip McCormicks and the Wilson Combats. They are well made and use good follwers. Some are 8 or 10 rounders too. They are expensive but they don't crack or cause jams. Long lasting quality IMO.
The one in your pic always cracks apart at the notch in the back of the mag body right at the bottom of the lips causing the lips to spread apart and get thrown in the canal.
In looking at the Wilson, that notch is rounded. The McCormick is angled. Both types seem to leave more meat on bottom of the lips for strenth.
Save the spring and follower, ya never know.
I grabbed a bunch from a show recently that are sealed in brown paper. The guy says they are mil. contract but I don't know how to tell. The followers don't tilt so I bought them. They have no markings on them that I could find. I'll try one out next week and let ya know.
Also I have a couple standard Shooting Stars. The notch is angled but the followers tip forward. So far (multiple thousand rounds) they have been reliable but time will tell.
My Mecgars have been reliable even though I've been told others have had problems w/ them. Strange thing about them is that they won't trip the magazine safety inside of the Marlin Camp 45, so I need to keep them separated from the others.