Mine have not come in yet, I asked for a glow and a bravo. The Berg and Serpent are the two discs I've heard it compared to in flight.
Have you gotten to throw it yet?
I just got home and took it out in front of the house to throw it, along with one of my K2 Bergs (what they now call "K1 Soft"). I threw straight shots, slight hyzers and anhyzers, and bigger hyzers and anhyzers.
The Lone Star Glow plastic is a bit less flexible than the Kastaplast K2, but they feel pretty similar. I threw 16 shots with each disc, one after the other, at ranges from about 120' to 160' (which is what I use a Berg for). They flew almost identical lines on all of the shots, usually landing within 3 feet of each other. They also reacted the same way when they hit the ground on similar angles.
For me, it is very, very Berg-like, and I consider that to be a compliment. I like the Berg and I like this disc a lot. Kastaplast describes the Berg as 1/1/0/2 and Lone Star describes the Armadillo as 1/2/0/1. In my small test, I did not see much difference at all.
As far as the feel, they have similar depth. The Berg feels like a thumb track, with a high rim, then a lower spot, then a slight dome in the middle. The Armadillo has a raised rim, but then it is board flat across the middle of the disc. Because I place my thumb near the rim for approach shots, they felt the same in my hand, but if you like to put your thumb near the middle of the disc, I think you will notice a difference between the two.