ocz generally uses high quality chips and such and i guess they run a little faster than the value rams and OC well usually. other brands such as g.skll, mushkin, patriot and others often offer the same chips on their rams sticks but for cheaper. if you're really looking for overclocking RAM, do some research here, google, and on extreme overclocking forums and other places dedicated to overclocking. you're sure to find plenty of good info. about good RAM for such a purpose.
you're not overclocking? well then I wouldn't bother with OCZ unless you just like to buy the most expensive parts for fun. value ram will probably run just as well and for half the price. my patriot value ram benches higher than OCZ's lowest price RAM of similar specs...and it was still way cheaper. in addition, it overclocks better than most!