I average about 10mph or 16kph on my e-bike, and gets passed by routinely by 'normal' cyclists going faster than my pace. E-bike users do not necessarily ride faster; I use one to help with the many hills in my area, not to go fast. I don't think it'd be fair to force me to use roads and mingle with cars just because I use an e-bike.
My wife and I got electric bikes about 8 weeks ago and they have been great for running errands in lieu of single-occupancy car trips. We live near the Interurban Trail/Aurora and the e-bikes enable much easier access to a variety of stores, restaurants, and parks, which are not easily walkable. We now appreciate the nearby bike lanes and quiet streets for making longer trips to bigger parks or neighboring downtowns like Edmonds. We recently had wanted to return to Capitol Hill to enjoy a more walkable neighborhood, but so far bikeabilty has been an excellent substitute. Plus, in four years there will be a light rail station near us to offer yet another alternative to car trips. We feel lucky to have these options in our "suburban" location.