I'm pretty much the norm as well - I tend to call '10' but know that is a quirk that most stage managers I have met don't share.
The current show that I am working on we have quite a close knit and rambunctious group of young actors who still, after nearly 200 performances can still be surprised that "places" is called so close to "5" and thus their places call gets dragged out....
In an effort to light a fire under the repeat offenders (men's dressing room) I at one point started standing outside their dressing room door at 5 minutes checking my watch. It worked so well that we had places in 2 minutes that night, which totally screwed over the PSM's "cheat" of leaving a 5-6min buffer because that is what we were used to! Which leads to actors at places for 3 minutes wondering what is "wrong"
It's not a perfect science but we're learning how to adjust with each day to best get the show up on time.