This comment is a response to multiple people and some of my thoughts and things I heard when I called AOA and spoke to one of them about it.
I was told that the rattler bottle can be swapped out, and if you want it with the 700CC bottle, they will send it installed for another $200.
I love integral magazines personally as they simplify many aspects and the entire system has less possible points of failure overall. For example, breech seal o rings are not a thing you need to worry about, nor are broken plastic magazines that slightly miss align when a bolt is slamming through them at high speed. Plus, if you take the aea terminator for example, it's magazines hold 10 shots so you're getting 50% more on the rattler.
I doubt we will see calibers of the rattler below .357, although maybe bigger. One person told me a .45 was in the works. I was told that an engineer working for LCS wanted to make bigger calibers but they didn't want to so he worked with western big bores and made the design just different enough to not violate patent. If you want a .25 rattler, why not just buy a huben or an lcs? I'm a huge huben fan, have both the .22 and a .25 and I will say if a .35 huben existed as well that made similar power to the rattler and had similar capacity, I would not be interested in one.
Regarding the sliding of projectiles in the magazine, on my hubens this can cause jams. Once I swapped to snug ones I never experience jams anymore. Although hubens have a tendency to do better with wider diameter slugs, in my experience. For example, in my .25 huben, NSA .250 slugs are horribly inaccurate, .253 Zan slugs are much better and .254 AVS slugs the best. My .22 huben shoots .2225 slugs that I swage. Obviously none of this means the rattler or lcs would be the same, but they could be.
I do like my huben triggers. I've heard the lcs triggers are not quite as good but not nearly as bad as an aea terminator trigger for example.
Sometimes my hubens snag a beard hair.
I couldn't care less about lack of full auto functionality. It may be for the best although I'm not against it. I've talked to people with lcs sk 19s who say the novelty wears off pretty fast and they almost exclusively shoot in semi. Pulling the trigger as fast as I can I can dump a huben mag nearly as fast anyway.