Personally, in my own opinion, it is fast at loading most elements such as images, HTML, CSS, and Macromedia Flash objects. However, it does have problems with objects rendered from Flash 8 and 9 that I've heard.

did you make it yourself?
If your talking about the program -- no. It was developed by Moziila; if you are talking about the article -- yes, this is completely written by me.

Does it have alot of fastness?
Well, it is fast by itself. If you want to make it even faster, you can download an extension for it called FasterFox... which loads pages faster, but increases the server load.. and that can be bad for sites like Flashkit.