I use my Acer C720 Chromebook on a daily basis as I find Chrome OS more efficient in its use of the CPU than my Toshiba Satellite C660-15R Notebook running Windows 8.1 Professional as Windows 8.1 Professional seems to be a bit of a CPU hog and constantly runs the CPU on 99% or more which makes it a bit slow for daily use. I'm running my Toshiba Notebook in a dual boot configuration with Windows 10 Technical Preview.
Windows 10 Technical Preview is for more efficient with its use of the CPU, but since it's only a Technical Preview of Windows 10 which is still in active development it's not quite at the usability level as if it was a Windows 10 Release Candidate build, meaning that Windows on My Toshiba Notebook isn't quite at a level of usability for a desktop replacement yet.
Where my Acer C720 Chromebook is my daily go to in Laptop terms my HP Stream 7 Windows 8.1 Tablet is my go to Tablet as well as my go to Windows Computer, I also have a 2012 Asus Google Nexus 7 Android Tablet that used to be my go to Tablet, but my HP Stream 7 is now my go to Tablet as Windows 8.1 is far more capable as a daily use Tablet & the ability to add a Micro SD card to boost the amount of storage is far more convenient than having a fixed 32GB of internal storage like the Google Nexus 7.
Windows 8.1 feels far more usable than on my Windows 8.1 Pro Notebook & Windows has for more useful free apps than what Android has got.
My Nokia Lumia 925 has now become my go to phone over my iPhone 4S, as the camera is better than that of the iPhone 4S and Windows Phone 8.1 has got more cool features than iOS 8 including Live Tiles instead of static icons and Live folders that allow the Live Tiles to show all their information as well as scroll through all of the items in the folder unlike static folders that just show icons. Also the battery life is far better than that of my iPhone 4S.
My iPod Touch was used as my go to device for games that I couldn't fit on my iPhone or for features in iOS 8 like sms relay, but now it's mostly used for games that I can't get on Windows or Windows Phone as well as for a quick camera, for listening to music that's not on my Nokia Lumia 925 or for watching YouTube videos, Facebook, Twitter, Google Plus & Instagram when my phone is on charge and I'm uable to use it when away from a wall socket.
While I still prefer my Acer C720 Chromebook over my Toshiba Windows Notebook, I prefer Windows over iOS for a go to phone. I prefer my HP Tablet running Windows 8.1 over my Nexus 7 running Android even though the HP Windows Tablet is exactly the same screen size it's for more usable in the fact that it runs the same apps and programs as my Toshiba Notebook and the full Microsoft Office is more usable than the Tablet version available for Android.
Speaking of Microsoft Office for Tablets it'll be interesting to see how many of the Desktop apps Microsoft make Touch friendly version of for Windows 10 Tablets since the current Microsoft Office Touch preview is just the three apps that Microsoft make for Android & iOS (Excel, PowerPoint & Word), it'd be nice if they make Touch versions of all of the Desktop Office apps as Microsoft Office Outlook is far more capable than Calendar, Mail & People is (but People has a nice feature with the ability to connect to Facebook & Twitter to show Tweets & Facebook updates as well as letting you post to Facebook and Twitter) The three individual parts of Outlook (Calendar, Mail & People) are handy if you don't have a Microsoft Office subscription but, there no replacement for Outlook if you do and it'd be silly of Microsoft not to make Touch Friendly versions of Access, Publisher & Outlook for Office subscribers that use a Tablet.