Fountain of Knowledge

Hello!

Has anyone read Dwight V. Swain's "Techniques of the Selling Writer"? I was reading the section today about "Motivation Reaction Units"...an explanation is broken down here, if you have never heard of this and are curious: http://katieganshert.com/katie-ganshert/motivation-reaction-unit/

Anyway, I've been pondering it. And I'm not sure I understand it. It seems sort of obvious to me, yet Swain writes about it as if it's some technique you must master if you intend to write well.

"She was nearly asleep in bed when she heard the sound of her front door ease open. Bolting upright, heart racing, she listened. "Hello?" she called."

Alright, what's wrong with this? Applying what I think I understand from the MRU explanation on the link above and also from what I read in the book, perhaps I should have written, "...Her heart racing, she bolted upright and listened." But I think the former sentence reads smoother and has more impact. Am I wrong? I mean, I suppose one is as passable as the other but I don't see one as being "wrong" or off-putting...Does the former example defy the rule or not? I don't even know.



PS. No offense, but is there perhaps a more bustling forum similar to this one, where posters can discuss writing? I see the last post here was not even in 2012 but I can't seem to find anywhere busier when running searches. Which is a surprise considering this is a website for writers.