I was thinking of the same. I love what the RZX does with displays and effects, but here is what I've gathered from many hours online:
1) The RZX requires ALOT of power. I use a Mac, and you would need at LEAST an i7 and 16 GB ram, which is pretty much only on their newest laptop ($2,000). I use an i5 8GB ram, which technically is the minimum requirement. However, MANY people, including Pioneer mods, say you should look at the recommended requirements (above) for smooth performance. Anything less, apparently the CPUs go nuts and fans fire up. I also heard some other not so great things on it for the price you pay.
As much as I want the RZX to be the one, I am going with the DDJ RZ. Much less power consumption, and does a lot with effects. Down sides (for me) is lack of dislays on unit (I think the waveforms in RBDJ are very small compared to Traktor), and some layering of effects the RZX can do. However, it's $1000 less. My plan is to use the DDJ RZ until they clean up the RZX, or come up with a true stand alone (with flash drive USB capability) unit kind of like a 4 channel XDJ RXJ.
My problem is finding other add on units to supplement my mixes. Lack of maps make it tough. I also know the RZX has much higher sound quality with 96 kHz, but after researching that, most say you're fine with 44 - 46 kHz. Both are 24 bit.
It is a tough choice, but since I don't plan to use video, and not going to pay $2000 for a laptop after $3000 for a deck, I figured the things I will lose going to the RZ isn't really that much compared to price and performance. Besides, the RZ has a huge amount of features and options, so I'm sure I will be happy with it. Hope this helps a little.