alt Hacker NewsThe iPad's Audio Unit applications unfortunately pale in comparison to even simple desktop plugins. You won't find any Vital or Serum-killers on the App Store, and you definitely won't find software like full-fat Spectrasonics or the U-He instruments. The iPad can do some audio work, but once you stop using it as a digital 8-track or a MIDI machine, you are instantly outclassed by even a $300 Windows laptop running Reaper or Pro Tools.
The iPad excels in performance. Like I said, if you're using a DAW a regular computer is better. The fact remains that audio apps for the iPad are plentiful and cheap. The App Store only approach has made the iPad a more attractive target than Android by a mile. The iPad apps are also screaming deals.
Your comment summarizes the people's inability to appreciate the iPad on its own terms. "You can't run Pro Tools!" is such a silly complaint. Moog, Waldorf, Arturia, Roland, Akai, Eventide, etc etc etc they are all on the App Store and work very well by touch. There are of course a ton of indie apps as well. No, they may not be as "powerful" as some of the ones you mentioned but they are designed to work in a different way than the computer plugins do. And they are priced much much cheaper. Use a computer for computer workflows, use the iPad for things that it does better.