Do ground glass joints hold a better seal than a standard joint? What makes one better than the other?

As long as there is a seal, all is good.  In fact even if there is a small leak, there really is nothing wrong.  It will actually cool the smoke or vapor some.  People like the ground glass joint for its cleanliness and the extra skill it takes a blower to make.

For ease of use a standard pull bowl is just fine.