Advantages:
Well supported and lots of resources available who have certifications, but mostly used in Financial Institutions. Integrated add-on for Flex, Web Services, Silverlight, and Web HTML. Framework issues can be easily taken care of with Odin AXE framework, which uses XML and simple interface. Lots of resources are available who can work on and use QTP.
Disadvantages:
Ability to recognize complex UI and dynamic content hinders the tool. Mostly used in Data-driven web testing, which makes use of Excel sheets; easy for the user to use, but may cause issues in maintainability. Windows System only focused. Not suitable for Unix-Clones and Mac OS. High deployment costs, and later will incur maintenance costs also, as each programmer has a different coding style and the new user has to learn and then work on it. Learning curve for it is not steep, as users are available who know VBA and VB Script.