In general all the browsers work, but.... The problem is that most browsers have some things they do different. Most notorious is IE and the especially the pre 11 versions. We always try to test our application in at least three different browsers. One developer always uses chrome while the other uses firefox and the testteam uses IE.
Things we see most is not refreshing correctly and most of the time we can workaround it.
And Safari on a Ipad is a different categorie. Most of the time it works, but previewing documents etc works just different on a mobile device then on a laptop or desktop.