My initial resistance was that I was slower in acquiring the dot. I've improved. And switching from a Trijicon RMR to a Leupold Delta Point Pro has helped, too.

Another issue is that red dots really show your shake. Of course, you shake just as much without a red dot. But it's not as noticable with irons as it is with an RDS. The upside is that it does a good job showing you things you need to work on.