As teased in the new Serato videos last few days, new Serato update brings real-time stems. They already have flexible beatgrids.
We are, once again, last... I know they are on the roadmap and I'm thankful for that kind of transparency for the first time, but that "in research" should become "we are proud to announce" as soon as possible, before the year ends hopefully. Traktor user base is more than electronic music DJs.