Well, for my business I use an iPad 3 and an iPad Mini 2. They both work fine, and one of the reasons I picked the (2nd-hand) Mini 2 was that I needed something that would just work with the mixing desk etc - Android devices offer better price-to-performance ratios, but finding one that would definitely work (ie, no issues with screen resolutions etc etc etc) wasn't trivial.
I do most of my computing on a laptop, though, and can't see that changing any time soon - I do quite a lot of typing, and use software that isn't available outside of a desktop OS: REW, XSim, Hornresp, SketchUp, as well as some video gaming.
So, I probably won't be buying the latest iPad. You can get a whole lot of music, or a couple of decent microphones, for £1000.
Chris