I have riden in many group rides.
The new starting line is a great addition allowing us to warm up and keep spinning is even better. I like how you live in your own little bubble while in the ride. You only see nearby riders of people in the group. Group texting while in the group is good, that it is easier to chat among the group. The new feature that teleports you to the start line. IMPORTANT - your previous miles and time you have ridden DOES get saved as a separate starve ride. (Good or bad you decide)
When I first logged in 1 hour early. I wanted to ride for an hour before the group ride. This is where the problems started. You only see nearby riders who also are in the same group ride you will be doing in the future. I think this is bad. I should be able to chat and see who is near me. I am constantly looking to see who is near me so I can speed up or slow down to join them.
I am not sure how this will work. But for those who do NOT join the group when they enter. They are NOT in the group ride and can not chat with us. So if they either come in a few seconds late, or want to join a ride after they have ridden for an hour or two they can not without stopping and saving their ride and logging back in. Also this same bubble I mentioned earlier will not allow you to chat with your friends during your group ride if they re just riding a normal ride. You should be able to talk to both riders in and out of your group.
Overall it is much better than what it was and I am sure Zwift is working on more still. Just thought I would give you my feedback to let you know.