I played on realm 15 and leveled at both Dwaft and Human starting locations. At least I tried. There were way too many people, so many that I couldn’t finish any of the quests because of the sheer number of people and the number of fast tap classes. So whatever setting that was it needs to be dialed way down.
I also played on realm 3 in the NE start location. Also crowded, but more reasonable to where I could ultimately get quests done. I’d say this one was about right in size. Lots of people on start, it spread out after moving out of the first zone and there was little delay in getting this done. Then when I went to darkshore, there was no delay.