Same wifi issues. Ipad2 and Mini both on 6.0.1. I sit at my living room table and stream music from macbook pro. Mini just can't do it. Bounces from full strength to no strength. On the mini, I can listen to about 5 seconds of a song, then it stops, then starts a little later etc. IPAD2 streams the music perfectly, and consistant signal strenth in the exact same location. Something is wrong with the Mini's wifi for sure.
Have the exact same issues. And I am using also ipad2 and iphone5 as reference. I use AirPort Extreme and have not changed anything in my network to cause this.
Hope this is software. Else it is going back.