They're completely different. Neither is better, and since you're a "novice-intermediate" I'd say don't even try going for the NS9kX; it's too stiff and unforgiving, and you'll get no power.
the ns9ks? or the at800 or a diferent kind i am partial to yonex though. i have had my at700 for several months and i would like to buy a new one
How can anyone recommend a racket to you if they don't know you? What style of play, what is your budget etc. etc. What do you like / dislike in a racket? For a novice - intermediate I wouldn't spend too much money just yet until you know your own style and preferences. There are many rackets on the market not because of the range in budgets players have, but to suit a wide range of preferences. There is no such thing as the best racket, just the one you like best. AT700 and NS9K are both great rackets - neither is better, but IMO they are not recommended for novices.
erm..at700 is better ...if u're really getting at700, dont get thick grip..it's quite hard to generate power..if possible.. jsut leave the original grip..as it has heavy head ns9k is like light headed offensive racket..for me it's kinda like unstable.
hmm..hsvnt try at900 before..but wat i heard was the technique 1 is better..? no idea tho...i might gonna get the power 1 when i go back to m'sia this year