i would wait for the new ddj sz2 to come out....the price of the original sz will go down...between the ddjsx2 and the ddj sz the ddj sz has the better sound card...
Both are good depends on your budget how how you will use them. SZ would be the best to get if u need 2 laptops connected or like the bigger platter/size
I've had my SZ for 2 years and i must say this controller is worth the money...perfect for w,e gets thrown at you...the sound is superior the job wheel and functions on the platter are exactly like the 2000's just minus the screen dispslay....well worth the money!
If you decide to get the SX2 I would say to consider looking at the Denon controllers before you purchase anything.