I am using the plugin fine, although there is a lot of weird activity that may be an issue with my server; I haven't optimized it, and I think I am having caching errors that make the mapping do odd things, like login page reload loops, and having different login states for different domains.
I was poking around and saw that I could change the home and site-url, as well as a bunch of other places where the domain shows up, on the network site list.
I've spent a lot of time going through the threads here, and I can't quite get a grasp on a best practice here. If I can change the URL by editing the site settings, do I need the mapping? My network is a small collection of sites, each of which have a single domain pointing at it (A record pointed at IP address).
Is there a reason I should use the Domain Mapping plugin? I can easily set all these up manually, as they are migrated in.