The Go-E OnWheel is making progress through its Kickstarter backers.
Europe seems to be getting deliveries regardless of order or Batch 1/2 early bird possibly due to battery shipping compliance for other regions. I'm deducing this from the campaign comments on who has identified they have received theirs.
Sinclair Zeta was belt driven motor to roller, so history has changed.
I beta tested a domestic inventor's Commuter Booster project, that was an RC outrunner direct to wheel friction drive. Everything so far with Go-E is looking good for a quality product to exist long term, despite people's impatience.
With time passing a better battery has been bulk purchased, and they have leapfrogged Add-E by designing their own motor. It sounds like they were testing it at 800W, but Add-E is 600W max, so seems they are matching it with headroom for reliability.
I considered the Add-E earlier in 2014, but the cost and limitations of it made it a no-brainer to put that large chunk to a nice Bosch performance line geared hub rigid 29er commuter.
GoE Onwheel got my backing with the throttle option stretch goal in the campaign. Having used powerful friction drive, I liken it to a 2 stroke motorcycle relatively in legal electric hub and mid drive world.
Add-E controls were limited to bottle top, so to have power on demand, I'd have to go through on/off and startup delay. The components are still much like the GoE prototype, packaged handsomely but not developed technologically.
A nice light pedal bike that mostly doesn't use assistance, but has the friction drive ready on demand, is the best use case for friction IMO. The friction drive RC outrunner motor noise isn't a pleasant modern bicycle experience. I think that is fine as it moderates your use to minimum if you are a pedal bicycle enthusiast. Making the same trip speed but needing to not sweat for an appointment etc. during the day, but ready to ride to your 80% limit for fun on the way home. The Commuter Booster inherently named the scenarios it suits very well.
For the steel Schwinn example, a clutched geared hub will freewheel so you can have cheap simple quiet hub motor power on demand would be my choice.
My wishlist to replace the friction drive would be a small volume custom made fair weather light weight geared hub closer to a large dynamo but on higher voltage for low torque 10-25kph below average trip speed assistance that keeps sweat down and ballpark similar trip times, legal, and low battery consumption.
Current pedelec torque is really good for mountain users, my scenario for slight hill assist but generally just the feeling of a tail wind on demand, able to pedal regular trip times regardless of conditions... but the human is truly the primary drive.