Tablets are perfectly suitable for work, and I've been using iPad 1 for (also) work since Day 1 back in 2010. I also heavily use iPhone for work-related purposes.
However, Apple's software as a rule is lousy; the iOS default apps have always been ridiculous from the point of view of their limited functionality (which is why I never bought the original iPhone), and as of iOS 7, Apple's default apps now also
look absolutely hideous.
Fortunately, there's a huge amount of 3rd-party iOS apps to take care of that. I use DocsToGo for office files on iOS; integration with Dropbox is a must for me especially for cross-platform compatibility, but Apple's office suite does not provide it, so that Pages/Numbers/Keynote is worthless for me. But then, I'm used to Apple's software being worthless and ugly.
Here again, though, one can see the advantage of the iOS environment over Android: I just can't find anything as good as DocsToGo on iOS in the Android environment. Although there is DocsToGo for Android, it's totally inferior compared to DocsToGo for iOS. The Kingston Office suite for Android is impressive for free software, but is likewise inferior in its interface usability compared to DocsToGo for iOS.
This is typical when you compare 3rd-party apps between iOS and Android. The iPads' biggest advantage over Android has nothing to do with Apple, but with the universe of great apps created by 3rd-party iOS developers.