I posted this on the RM Ning sometime ago and got a good response, so I thought I'd do the same here.
Firstly, I should say I'm referring to iPad's here, not iOS devices in general - the larger screen is a bit of a must for my eyesight. I'II admit, I used to think iPads were just toys and I had little time for Apple as a company (I still think that now), but I've been quite amazed as to whats going on in the musical world with iOS. I tried mobile music making on a (fairly weedy) android tablet, but with the latency it had, it was virtually useless, I wasted some money on apps that weren't able to do anything decent.
Anyway, about six months ago, I bought an iPad 4 off a friend and he suggested a good slew of apps to get started with. I sold that on and I've now got an iPad Air2 and an Air (both 64GB models) and oodles of music apps. I actually haven't started a project in earnest, but I'm getting there
I've had to adapt to Apples's rather cryptic approach to file management / transfer, which has been quite a learning curve in itself. In general I'm amassing the knowledge to create a different way of working on these devices.
Personally, I now feel it 's a great platform for music making, am interested to hear other people's thoughts / experiences - particulalrly with regard to ambient music.