Any speculation on whether a particular system wiill perform satisfactorily with Extremes is just that –speculation.
The true requirements for Extremes will not be known until the completion of beta testing, if then.
We spend much time answering complaints from users who say their systems meet the published minimum requirements for SS 2008.
Meeting such requirements is not the whole story. How you have installed SS, how you have configured your system, what else is running in the background, all affect the performance.