Although not an answer to the actual question, I think that professional software should not use 3rd party components unless really necessary. It usually makes the application look more professional if you design your own visual components, specifically for your application. And, when it comes to non-visual components, what can they do that you cannot do yourself using Windows API? Really, if you are a competent Delphi/Win32 API developer, you can probably do most of the work yourself. Not only will you learn from this, but you get precise control over the functionality.
I am not saying one should never use 3rd-party components at all. Indeed, you might need components for highly non-trivial algorithms, encoding/decoding of complicated file formats etc., but in general I feel that there is too much fuzz about 3rd-party components.
Please do read the comments for some interesting discussion (and some clarifications).