In recent times, one of the major factors when deciding what phone to get is the text messaging feature. An average young person will buy a phone based on the text messaging user experience.
i was young once, and i had no problem with the "messaging" app on symbian, and since i got the Lumia 800 i decided to show the differences between messaging on the N8 and the Lumia 800.
So in conclusion, the N8 has a full array of settings, it's fully customizable, has features like "save to draft", templates, conversation/inbox view, font size, MMS settings, multiple selection of contacts, among other things but its keyboard (portrait) is too small, no voice-to-text feature and there is no integration with your social media.
However, The Lumia 800 is keeping it simple with its nice keyboard, voice-to-text feature, and full integration with your social media, it lacks a considerable amount of stuff, stuffs like: no drafts, attachments limited to just pictures, settings limited to just 3 switches: facebook chat on/off, SMS confirmation and group text (which to me shouldn't even be an option in settings, it should be on by default), there are no MMS settings, no templates.