Because, not everybody here owns nor had play with an Omnia before. 
That's why they're checking things out, here.
And Omnians here should try to help them by providing answers from their experience. 
Information like this:

Will also be very helpful for peoples considering to be an Omnian. 
On behalf of future Omnians, Thank you.

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Added on June 27, 2009, 12:57 pm
No.
Same as your computer running Windows, crashes are normally caused by 3rd party softwares that you've installed.
Programs running at the same time or not close fully may have caused the lagging.
8 GB and 16 GB are the same except the storage space, it's the same like your PC's harddisk.
Updates are always good. It means that either there are new applications added, applications updated and/or bugs fixed.