Advantages/ Disadvantages of Citrix

There has been more and more press around Citrix. What are the benefits of using a Citrix-based remote access versus a pure net-based approach? Also how difficult is it to deliver a pure net-based approach versus Citrix? How scalable is a productusing Citrix? Finally, many browser-based ASPs claim that they are using a pure-net based approach as a opposed to Citrix remote access – is there really a competitive advantage? Thank you!