It's already been one year since Native Instruments has shown us where they see the market headed. STEMS is their baby and they have come out in full support of it.
First it was with the S8, the first controller to support this new mp4 format, then it was the D2, and I would think they wanted to make it a modular set up to compliment with other hardware. Then it was a more "entry-level" in the S5 and then an update that brought the STEMS to older NI gear and even third party mappable controllers. I was not kidding when I said it is their baby. It is clear that is where they see the market is going.
And with the one year anniversary of STEMS, they are bringing you the opportunity of saving on two of the current products that support this format until May 31. The S5 and the D2 are each going to save you up to $200 dollars. That is a lot of time to think and make a decision if this right for you. Usually NI does one month sales but you are getting two months, so no rush.
Official Information from Native Instruments can be checked