As a practical matter, this kind of installation is most useful where a high speed internet connection is available; a dial-up or a low speed DSL connection may not give adequate performance, and any disturbance to the internet connection means that tax returns cannot be prepared for the duration.

A major advantage is that tax preparation can be done anywhere there is an internet connection without requiring a local installation.  A major disadvantage is that the information is updated page by page only when the page is saved explicitly, or the user moves to a different page.  If the web browser crashes, all the work done on that page since it was opened will be lost.