[kayoone]

Mavericks works fine on my 2011 11" MBA with 4GB Ram. I don't use this machine for work, but it's still fine for everything else.

[hatbert]

I'd believe that, but your MBA also has an SSD, which partially masks the effect of swapping out pages. True, SSD is an option for the new iMac, but it's not included in the base price.