Odd this topic came up, I just debated all three guns (WASR, Storm & Mini) and after much deliberation I bought the Storm.
Reasons? First, the Beretta has great ergos compared to the other three, and making it into a nice "tactical" carbine is easy. Second, mags are readily available for the Beretta (92 mags) and if you buy a storm Beretta will send you 2 hi-caps after Sept. 13. Ruger will NEVER do this, IMHO. Also, the Storm is light and you can bump fire it really easy. I know that's a stupid reason to buy one, but sue me it's fun to dump 20 rounds of 9mm in one pull. The Storm, in my experience, is accurate and fun.
The Mini magazine problem is old and frustrating, and the accuracy isn't very good.
The WASR, while AK-rugged, is rough and crude and the ergos & sights of an AK stink, IMHO.
My .02 anyway.