In short order, you end up with a lot of clutter, confusion, and hassle. Rather than having a basic Bible window and a separate search dialog, you have a Search window which enables you to see at a glance both your search argument and the results of your search. Take a moment to look at the way the Search window is laid out. If you want to compare multiple translations, you simply open several panes of the same window, rather than a bunch of separate windows. While a great many of these features are unique to Accordance, the thing that really sets Accordance apart from other Bible programs is the fact that all of these features are brought together in a single, consistent interface element.
Accordance surely IS a valuable tool.
In my everyday work with NT research I often regret that there is not any access to the TLG CD from Accordance.