You may want to have a universal experience across all tablet platforms, but your iPad customers (who are the overwhelming majority by the way) don’t care about that. They want an app that looks good, feels good and has great performance.
I want to add that this doesn’t just apply to magazines, this applies to ALL iPad and/or iPhone applications. If you want to do a universal Application, do your iOS version first, then play like Google and make your cheap knockoff for Android. iOS Apps that don’t look and behave like iOS apps get dropped like bad habits from my devices. Being unique is fine, follow some halfbreed set of conventions because its where you find the platform intersections comfortable results in hideous applications that neither iOS nor Android users are going to love.