As I read this I was thinking to myself "why not both". I guess the obvious answer is "cost", but that's never stopped Apple fans before. With an Android device you can have multiple accounts and keep most of your data "in the cloud" which makes it easier to share devices in a family.
1) Cost? Not an object, tablets are virtually free. Less than half a day's wages if you are in an office job, a full days wages for Joe-middle-class. Granted, I work in IT, but for me a MacBook (either) would be barely above the price point of "impulse buy", any tablet is priced below that point.
2) "With an Android device ... and keep most of your data "in the cloud" ..." - why did you specify with an Android device? My documents are in the cloud and accessible on whatever device I happen to use (iMac at home, iPhone wherever, MBA or iPad in meetings). Work documents I keep on my employer's "cloud", personal documents of one type on my Apple account iCloud, personal documents that I share with my ex are on my Google account. Multiple accounts are easy.
A tablet is a smartphone in an easier to view and manipulate form factor, a smartphone is a tablet in an easier to carry form factor. OS is next to meaningless, except in my experience, Apple does a better job of making the same documents also perfectly functional on a laptop/desktop computer ... So the integration between home, workplace, and on the road is seamless. I'm guessing others will be getting there soon, probably the next group to get there will be Microsoft with the abomination that is Windows 8, provided they can get the awkwardly unwieldy UI and hardware trimmed down to usable.