Bill,
There are apps that work fine on either platform, such as PocketCloud, I use that for remote Windows server administration. Words with Friends works fine on both platforms.
Here's a few, I'm focused only on 10 inches tablets here...
Facebook, the app on Android is pathetic. Stretch-o-vision, clunkly, ugly, notifications rarely work. I settled on Friendcaster. It's decent, but not as quick nor polished as the iOS Facebook app.
Twitter. PHULGLY! Stretch-o-vision again, making swipes a awkward. And ugly. Did I mention ugly?
So I tried Slices instead of Twitter. It's great on iOS, but on a tablet, it's another stretched, awkward to use, program. Neither is enjoyable to use on a 10 inch droid tablet.
Tune-in Radio for droid doesn't offer custom URL's like the iOS version. Sure, there's other programs for this, but why?
The DrudgeReport app refuses to load anymore. It was slow when it did work, but now it won't get past the splash screen. iOS? No problems at all and it's noticeably quicker.
You like Zynga games? We do! The Matching With Friends is an addictingly fun game that takes little brain power and very little time. But if you own a Droid, you must put it down, then pickup your Apple device to play it as Zynga doesn't make a droid version. Gems is another fun Zynga game that's only available on iOS
Another oddity is playing videos. I like to watch WGN news, it's available over the 'net. It doesn't always work on the Droid, but works reliably on iOS.
Thus the reason why I don't suggest a 10 inch Android tablet.
If you can live w/o the games, a 7 inch droid tablet is a different game since the screen size is vastly smaller. But for 10 inch tablets, the king of the hill is the iPad and all the app goodness that goes with it.