"One of the interesting things regarding BB10 OS is that it has true multitasking. If you're running 2 apps, you're truly running 2 apps, honest-to-God, in parallel, it's not that the front one runs and all others are in some sort of a semi-sleep mode.
This makes switching between apps fast and easy, and when you switch back, the previous app is exactly in the state in which you left it. On my Android tablets, it's not always so... an app can be tossed onto the "disk" and live in a sleep mode, to be reawakened by the OS at need, which takes time and not all of them wake in the same state as they were.
Of course, true multitasking takes its toll; original plans for Z10 were that it should have 1 GB memory, and it had to be changed to 2 GB, because having a bunch of stuff from the OS itself in memory, and then multitasking apps on top of that, takes a lot of space.
But that price was paid, and it multitasks beautifully.
Also, any native BB10 app, written in C++ and using Cascades, is going to run circles around any Java app. What you get out of it is... smooth responsiveness. Things written that way respond in a split second, you don't wait for them, they wait for you.
Also that gives you much better CPU usage, which on a mobile device translates also to more battery life and less heating.
In truth, if you connect it to a serious monitor and a keyboard... you could make real desktop-style applications and it would be on par with a weaker notebook. Now if someone would start making serious desktop-level applications for BB10..."