Upgrade to Volcanic islands/maxwell/700 series or wait for their 20 nm counterparts?

hello citizens of Tek Syndicate, i'm currently saving up money for a new gpu, and I will be acquiring one next year (Q3-2014).I know this is quite early to ask, but I am simply curious on how will the architecture difference will effect on their performance. should i wait, or wait longer?  thank you.

only benchmarks will tell what the difference between AMD's new architecture and nnvidia's 700 series will be. if im correct they will be coming out september 25th ish(or the reveal atleast)