Much better than 3 dot sight - XS Sight Systems DXW Standard Dot Sight - Glock

In my case these sights took quiet a bit of effort to get in, that said the factory sights were a bear to get out, had to soak them in oil overnight and almost ruined a sight pusher getting them out. I think the slide cut on my gun was to low end of spec which is why it took about 4 filings with the XS sights before I could push them in.
As far as the sights themselves they are very robust and the sight picture is quick to pick up and at combat range pretty accurate once you get used to them.