I saw a couple eMTB riders ride up Roadside, faster than my kids can ride down it. We all expect riders coming up, its bidirectional, but we don't expect them coming up FAST like that. eMTBers change the use pattern on trails, its a recipe for conflict, it'll be interesting to see how it works out.
Do eMTB riders tend to exhibit a relatively higher degree of poor trail etiquette ?
That is a hard one to answer, but a couple anecdotes.
Last fall there was a guy doing laps on Floppy Bunny at Fromme with an ebike. Passed me and my 10year old kids on the road a couple times while we were doing laps on Bobsled and Floppy. Its basically shuttling, he had one hand on his bar most of the ride up, but shuttling is a thing. If you don't want to ride up, fine.
One of the times he passed, he didn't slow down even a little, whipped by one of the kids by riding through the Salmon berry bush sticking out into the road beside her. That was a dick move. If she'd wiggled in her line a bit, he would have run her down.
I have the kids move to the side when we can so people can pass us, and MTB riders, even fast ones, come up slow enough we have the chance. eMTB riders... not so much time, they ride up pretty fast and don't often slow to pass.
A couple weeks later, when moving to the side of the trail just past the first turn to the right on 7th, also where its lined with Salmon berry bushes, I had an eMTB rider rip by a foot from me and the kids without slowing down a bit. I call that a dick move, too. It doesn't kill anybody to slow down a bit when a slower group of riders squeezes aside.
In fairness, I've had non-motorized MTB riders do that, too. One not-e guy rode onto the 10 foot/5"wide skinny log on Lower Digger while I was spotting my daughter in the middle of her first unassisted attempt. If she'd had to stop, I'd have steaded her, and he'd have ridden into her, or fallen on me. As it is he timed it to surprise the shit out of me, and barely miss her on the exit off log. Jerky behaviour is not owned by eMTBers.
All of which is to say, I'm trying to not judge ebikers by the few jerks, like I try hard not to judge dog owners by what I find on my shoe... but its a bit hard when I'm standing it.