First of all, archaic doesn't mean it's worse. Second of all, the modifications to the tweeter done by Kharma is partly what makes the higher end Kharmas so special. With the 3.2 you get the same tweeter that was used in the older Exquisites. Plus you get a lot more with the 3.2s than just a different/better tweeter. Pasting from the website you get:
Pure silver coils in crossover
Double pure silver-gold internal wiring
Special internal cabinet treatment with advanced polymer
Signature series WBT connectors
They say the magic lies in the crossovers and the difference the internal wiring and silver coils make is pretty significant. What you essentially get with the 3.2s is the same sound as the upper end Kharmas minus the bass drivers.
Jtinn and other Kharma owners can describe the sonic differences much better than I can as I've actually never gotten a chance to hear the 3.1s. Essentially the idea is that the 3.1 gives you most of what the 3.2 gives you, while the 3.2 simply does everything better and you're really getting that world class transparency that Kharmas are known for.
If you can afford the 3.2s they are indeed a better pair of speakers. And they are suppose to be limited edition. Basically, the 3.1s are a great value in that they give you a lot of the 3.2's sound. While the 3.2s are a great value in that they give you what the older Exquisites give you minus the bass but also less drivers that should contribute to a more seemless sound. There's also a diamond tweeter upgrade available and I think it's highly unlikely that Kharma would "run out" of those Focal tweeters.