I have an Air 2 and ipad pro 2 12" and overall using the iPad for beats is dope.
Especially with things like Aum and all the AuV3's that are available. A combination of apps will get the job done.
Some of my favs are Korg Gadget, Koala Sampler, BM3, IMPC Pro 2, etc.
That said, you are limited by a few things:
The age of the iPad, the peripherals you do or do not have, the apps you do or do not have and the $$$ you do or do not have to put it all together.
That said, bringing it back to iMPC Pro /2, its a dumbed down version of the MPC experience but still has note repeat and more than enough features to put together some serious heat.
Hope that helps
Peace