I'm not yet impressed with Core-M, the hype (bark) may be worse than this bite. If Core-M continues to lack punch and underperform in real products the word of mouth will have the opposite effect and become a wet blanket for products. I keep hoping someone will figure this beast out and release a Core-M device that lives up to the hype but realistically it's just not going to happen with the current versions. It will take a new Broadwell iteration, I'll dub 5Y91 (you don't have to look it doesn't exist), or a Skylake Core-M may deliver, the details for which are currently unknown.
Now wouldn't it be funny if the rumors of a SP4 bearing Core-M is what's sparking sales of the SP3.
Definitely word of mouth that's helping the sp3. Before, many many people were buying the BS that the ipad is great and windows 8/8.1 is this terrible thing. I think windows 8.1 and the sp3 are a perfect combo.