I have a Dell Venue 8 Pro, iPad Mini 2, and LG G Pad 8.3 (also a Nexus 7 2013).
I love the Dell tablet, great build quality and it feels so nice to hold. But the iPad Mini is definitely my go to tablet. The apps run great (definitely no crashing or glorified web pages here) and provide a much better touch experience on a tablet than many Windows apps do. I will say however, the Modern IE browser on my Dell Venue definitely provides a much better web browsing experience than I have on iOS or Android. But for just about everything else I prefer my iPad or Android tablets more, so thats what I usually pick up.
I'm very excited about the Surface 3 though. All my tablets are 7 to 8.3 inches and I'm kinda looking forward to going back to a bigger sized tablet. The Surface 3 isn't as thin and light as most 10 inch tablets, but it sounds like Microsoft has made it comfortable enough. And I love the 3:2 aspect ratio they are using. That's going to be a great balance for web browsing, apps, and video watching. And it might do a better job being my hybrid laptop replacement than I though the Surface Pro 3 did (which was too big for me).
I suspect I'll still be going to my iPad when I just want a pure tablet experience. But hopefully I'll find myself picking up that Surface 3 a lot more than I do my Dell Venue or even Android tablets.