I think the extra $100 is for the DNA chip
that can be customized on a computer using Escribe or something like that..someone maybe will chime in with more info..
As I said, I have both. I've dissasembled both.
Things the DNA does that the RX does not do? Well, I have a custom theme on the DNA that puts the Biohazard symbol on all my menus. The DNA 200 Early Adopters Forum has a lot of very bright people on it.
Is the DNA chip superiour to the RX chip?
Yes. It is more complex, has more options, and you can while away many enjoyable hours playing with it. You can even get a Simpsons, or Family Guy theme!
If you travel with a laptop, care more about the gear than the vape, consider yourself an "audiophile", and feel that complexity is the primary determination of value, the RX might not be for you. Get the DNA version.
It honestly is a superior mod.
Is it worth 3X the price of the RX? Well, from a practical, utilitarian perspective, they perform the same function. The RX has a smaller screen.
Either the RX, or the DNA version are a good value, depending on what you want.