I will admit that the GUI is easier to use, but that is often the problem. People mistake ease for right or the best way.
If you use the scripts from the GUI, thenI hope you check them before you run them again. In this way you are not "depending" on the GUI, you are using it to your advantage. If you use scripts, you must also determine the proper order in which to run them. You don't want to implement a FK before creating the table, so you are not depending on the GUI in this way either.
The point was that so many people use the GUI for all changes, to development and production. This is where they get into trouble. How many times do people post in these forums somehow assuming the EM does some "magic" when it alters a table instead of reading the script and finding out that it really drops the table and recreates it.
I do use the GUI, but as edo_2000 uses it, usually when I don't remember the exat syntax. However, for tables and other objects, I want the documentation and so I script them and their changes. In this way, I can add my comments, or change them if I am not sure. I think that by scripting you are more likely to stop and think rather than just doing something.
As far as RedGate's tool, I have to apologize to Simon and the crew at RedGate, I haven't tested it yet. However, rather than a GUI based tool like EM where I am not sure what I want, I'd rather have some more intellisense in QA where I can type "attach database from file" and have it start prefilling the path based on what I type, like the address bars in W2K or IE. I really dislike depending on these tools if I am not 100% sure what it is doing in the background. Too often the author had a different philosophy than I.
Thanks for the comments and keep them coming!