Its a small differance with home being a "desktop like" situation vs the seperate task management screen. WebOS took the card metephor and applied it the best- you have to see it in action to get a feel for how it works. I know android has had that form of multi tasking for a while I think 4 brought it in? the revision where they attemped to get rid of hardware buttons- and it still gave you basically a entire history of your apps...but then again droid and ios users never really dismiss their apps actively as they have been conditioned to let the system handel them- and from the 1000's of "why is my battery dead so fast" posts etc. it does not always manage your active/inactive/suspended apps well.
One big thing I do not like on my black berry - is if I am composing an email, I cannot go back and look in other emails- I have to save it as a draft- in WebOS the compose was a seperate card so I could go back and forth at ease- also browser I just made multipule cards rather than tabs, but they are mostly the same there. The gestures on BB10 are a mixed bag, I see why people do not like them- esp coming from WebOS where navigation, management etc. was all gesture based and very consistant throughout the OS and apps- my Pre3 is shattered so I cannot really video it- but I cna video my TouchPad, its app pages where a little worse than the phone version, but its notifications where heads and toes above and beyond awesome- really the best I have ever used.
As far as getting used to a screen keyboard vs a real one is this- on a real keyboard you type accurately and notice your typoes and correct them- with the virtual keyboard you just dont give a shit and keep typeing away and let the auto correct do its thing- a physical keyboard cannot really tell "well he pressed Y but his touch was 40% on T and also 5% on G - then couple that with the previous letter and make a smart choice on the detection or autocorrect.