Octavia Greenline III Estate or wait for the new Fabia Greenline Estate 2015?

Hello all, 

I might potentially be in the market for a new diesel estate car. I'm chiefly concerned with economy and storage. I like to keep my running costs down as I do 15k miles or so a year. 

What do people think would be good? I'm tempted by the Octavia as people say it is higher quality than the Fabia range and it has a bigger boot space. (I transport my drums around a lot). However, the new Fabias look quite nice and they're bringing out a Greenline model this year which is said to be even more frugal than their current Greenline models. (Although I'm aware real world figures are a lot less). 

Anywho, It'll be nice to hear your thoughts.