Is the Core i7 upgrade worth it on the Haswell Air?

Considering buying one of the new Haswell Macbook Air's(probably not for a month or two) and I'm wondering if the Core i7 is worth the extra $150. I use Eclipse, Android Studio, Chrome, Firefox, Spotify, Komodo Edit, Filezilla, sometimes light iMovie or Garageband/Cubase usage.
Also, how hard is it to upgrade the RAM yourself on an Air?