I have Samsung Galaxy Tab S 8.4 16gb. 128Gb external sd card. I use it for everything while I'm travelling (iFly, email, teamviewer to connect to my desktop, even an occasional game). I paid 1/2 what an equivalent iPad would have cost at the time. I have an iPad mini (old version), that I use for testing. I would rate both devices as equals. If you are engrained in apple ecosystem, get an iPad. High end Android tablets can cost as much as iPads. I have had samsung and asus tablets. never had a nexus, but they're nice too. You wont go wrong with Samsung or Nexus.
The advantage you get with android is not having that horrid grid of icons as your only view. I have a few widgets and a couple of icons on my primary home screen (calendar, weather and email), and on my secondary home screen (timer, shortcuts to FAR/AIM and iFly).
Another advantage is being able to root and customize the OS. I run rooted (similar to jailbreak) and I run cyanogenmod. That's a highly customized and super clean / fast ROM. (ROM is a slightly misapplied term to indicate a modified Operating System. It comes from the fact that the OS is normally installed into Read-Only Memory). I control what is on the tablet. It's not necessary, though, the ROM that Samsung ships is quite nice (just a bit bloated for my taste).
BTW, I dont recommend that every user should root and install custom ROMs. You can permanently break your tablet doing this and you can expose yourself to malicious software.
my $.02