Pocket-Lint: Having that slightly larger screen on the iPad grants a lot more space to play with the tablet's music making capabilities. There is room there for extra sliders, bigger buttons and larger instruments. The result is a selection of iPad music apps that really do the most with the extra screen size available.
Some of these apps are so complex that you could quite easily produce an entire song using only them. Whilst Pocket-lint is yet to try and turn out its own record using just a tablet, it would most definitely be a tech first.