I've designed several web sites, including a couple of years as the webmaster for a Fortune 500 company, and was probably the first user of PHP on Mac hardware. Nowadays, I develop Mac applications with the Cocoa framework.
I haven't experienced many problems with Safari. It does a good job on standards compliance. In my experience, it's the "Internet Explorer" workarounds that cause a lot of grief.
Amen.
I haven't been on the "front lines" of GUI development for a while a Google search shows that my impression of Safari is a few years out of date. It looks like it's considerably less buggy than it was in earlier releases (then again, what isn't? Oh yeah, IE.)