I was referring to the 758 (non-classified). Get classified only if you want to go all out with water or LN setup and target 5Ghz. For upto 4.5Ghz, 758 or even the 757 (the LE model) may be good enough. All depends on how far you want to go with OC. I settled for 758 because of it having a very stable PWM and my goal was 24x7 4.4Ghz with HT ON, which I achieved.
I haven't used Asus Rampage II Extreme or the classified in person. So, my knowledge is mostly based on what I have read online. Between the two of those, I would go with classified just because of EVGA. EVGA has a huge and very strong community which responds to your calls for help, and excellent customer service of course. Returns are handled really well. OC wise, both are almost same, may be classified has a slight edge based on merely the top OC numbers people are able to churn out.
Define your goals (the CPU clock, the memory clock, air vs. water etc.) and then go from there.