N9 for open source software, "tweakabilty", and Meego. 820 for stable Os (ironicaly), good web browsing and updates.

I used a 800 and ditched it for a N9 because of closed Os (very difficult to tweak the os or get open source software, although possible), and because most of apps are real crap (I can't count how many useless apps I found in the marketplace). 820 with wp8 and nokia apps could be enough for some though.

On N9, I have good and robust apps for my every needs, even though app catalog is really limited. Power of love vs money I think

Also, keep in mind that good community make good devices ...