My one dislike of the AUG is a number of the proprietary mags. The one this is depicted with being prime example, they just aren't sleek or pretty :/ If the A3 or F90 could come with something like a PMAG, those'd look amazing
I believe there's a conversion kit available for Steyr AUG's that accepts STANAG's (AR 15/M16 style magazines as you describe)
Of course the down side is that the magazines are a little less sturdy as is the case with AR mags, they only have one locking point (as far as I know) compared to the steyr AUG's mag which as two and I hear are far more sturdier. Of course I could be wrong but I personally think the magazines look great.
If it hadn't been for the "off" rail, I would have mistaken it for the actual AUG A3 (semi-auto) I've helped with disassembling and reassembling. Fairly accurate airsoft reproduction, if I say so myself.