Played around with the MSFT tablet at their Apple copied store. This thing was nothing but lag. Spell check was horrible as it would only correct common spellings - not the ones you would expect on a touch screen. Many apps like Mail and Messenger would take 20+ seconds to open and when I asked the guy about why it's so slow and expensive, he said "you should probably go to Apple since you anyways have an iPhone." I find this whole thing to be a joke really.
He probably said that because you asked "why is it so slow and expensive" and he figured you came in with a bias opinion since you had an iPhone.
Spell check on iOS is annoying and apps on my iPad lag and crash at times. I can't say anything about Mail and Messenger taking 20 seconds to open other than I would have to see it for myself to believe it. Maybe somebody trashed the demo that you were checking out. I run Windows 8 on a couple different computers and it doesn't take 20 seconds for mail or messenger to open.