The Simulation servers are good already.
The idea of No Collisions in Arcade is also good, but for some, it's a bit controversial for those who hangout with their friends and drive recklessly (yes i know this is going against the rules but the group is having fun, it's okay if it's not annoying other people) and try not to touch each other.
Some minor tweaks on the rules for Arcade like the save edit rules should be softer a bit, if neither person can hit each other, there should be less accidents caused by some save edits (what's wrong with having triples in Arcade tho?).
If one of the Arcade servers get their collisions enabled, the current rules should be good enough, but have the server's player limit at a lower amount like 2100.
Most people that seek fun over realistic driving will naturally try to join the server where they could do their things. More people attract more people, the said server might be the next EU2. The lower limit on the server is too keep Simulation servers' popularity not to drop too much.
All things aside, my current opinion on this whole update is neutral. I agree at some parts, and I disagree at some too. I like when there's balance between the playerbase, so, seek the balance if needed.