I have the 1up with a 4 bike tray, and it completely obscures the license plate on the two vehicles I use it on, much more then a NS Rack. I cant believe it wouldn't obscure the license plate on any other vehicle either.
Have also received a ticket for it in Vancouver. Was able to challenge the ticket after I started using the 1up license plate holder.
Having owned and use both a 1up w/ 4 trays and an 4 bike NsRack - I much prefer the north shore rack.
The NSRack is:
* much more convenient if your frequently using it, it's just there. I don't have to fold it up and down, move the license plate.
* secures the bikes better
* has held up better over time. (The one up started to develop significant play causing bikes to wobble a lot)
* it's lighter
* believe it puts less strain on the receiver when fully loaded.
That being said - my NS Rack has developed that shitty rusty look, and not being able to properly carry road bikes is a pain in the ass.
I think a lot of my issues with the 1up is going to the 4 bike trays, I think it would have held up better if it were kept to two. The aluminum bolts that hold the extra trays, have also totally seized, and I've been unable to reduce it's size.