Windows tablet all day long. I have always found droid tabs a bit of a let down. I have always struggled to be productive on one. They are, after all, phones with out the phone in most instances.
Windows tabs are shrunken desktop / laptops. I run a yoga with win 10. I love the ability to switch between tablet mode / standard mode. I can get so much more done. All the apps I use are in the store, and if they aren't, I'll use the web based one. My galaxy tab 10.1 doesn't even get a look in these days. My kids use it for what it's really good at. Playing games etc. The windows tabs are just more 'grown' up. My wife takes her surface with her, and when sitting at an airport waiting for a fare to come out of the terminal, she can sit there doing invoices, books and general admin for our taxi company.