I bought two of the 6 packs, did yours come in as series 1? Mine did, I was a bit disappointed.
My core15 came with a Hexmag, my first experience with them. That mag, in any AR, would fail on occasion to lift a round high enough for the bcg to catch and load. I'd still use it as I only use for target shooting, but after it did it twice in a 30 round load I decided to contact hexmag and let them know of my problem with their magazine.
To my surprise they replied in about 15 minutes. Asked for photos of the date/label side of the mag and a photo of the follower(my original hexmag has the red follower). After sending them photos, they promptly replied they were sending me a replacement magazine and it was the new Series 2 which corrected some issue with the original magazine.
Apparently there are no follower changes as they told me the series 2 came with an orange follower, and that if I wanted I could install my original red follower. I didn't change it, shot a couple hundred rounds through it in about 4 different AR's and the series 2 ran perfect.
Magwarehouse finally got those 6 packs back in stock so I thought I'd stock up on some. Unfortunately, while they came with orange followers, they are still the series 1 magazines as listed in the side. I would have thought since hexmag sent me a series 2 well before magwarehouse restocked, I'd receive series 2 from them. I contacted magwarehouse and they said all they had were series 1, and series 2 weren't available yet...
Anyways, I tried on of those magazines out this evening and it seemed to work fine. At least if they do malfunction, hexmag has exceptional customer service. If it was guaranteed to get series 2 mags at that price, I'd do it over P-mags to save a little coin, but for the series 1, I'd pay a little more.