Hey Smeg I have one of these and love it. It does take double stack mags. The things I like best about are:
1. It's built on a new Bulgarian milled receiver. One pull on the charging handle and you can feel the difference. The Bulgarian receiver is commonly recognized as the best AK receiver available today on the market. Even if it is not the best it still puts the smoothness of stamped receivers to shame. Also being a milled receiver it will hold it's value better.
2. The "H" in SLR-100H stands for Hungarian. These parts are from Hungarian full auto rifles manufactured in the 50's. These parts exhibit higher quality than the newer and cheaper ak's on the market. (I have two Romanian AK's). The Hungarian parts kit have the world recognized profile of the classic AK-47 along with the lightening cuts on the receiver's side. The barrel is threaded and will accept the early ak-47 bayo.
IMO this is an excellent value. I got mine last year for $475 + shipping from Classicarms. I believe prices may have went up a bit. Currently Classic's web sight is showing $600, but I got mine for less than the website's price when I ordered. It doesn't hurt to check.