I hate apps tied to different clouds
The big thing now seems to release an app that can only work with your cloud :(
This is the equivalent of having to have a separate disk drive for each program you run on a computer!
I've downloaded office for iPad but don't use it as I haven't got a 365 account, I'd rather use Dropbox or iCloud.
The best apps give you flexibility of use and I don't begrudge a fee for that usability, but I'm dammed if I'm going to pay an annual fee to store stuff on a cloud that I never wanted to use in the first place :(