Thank you for your reply.
So you saying that any modern, simply, full automatic Canon camera (listed on the website as a compatable with CHDK) can be used as a full manual camera thanks to CHDK?
CHDK gives you pretty much full control of available settings. However, there are some things you should be aware of:
1) As zeno says, it can't make up for missing hardware.
2) Using CHDK to control the settings may be less convenient than the equivalent in the native firmware, and taking full advantage of it may require more technical knowledge.
3) CHDK is hack
. Some ports don't properly support every feature. Some features may have non-intuitive restrictions or unexpected side effects. You should expect to experiment to verify the exact behavior on your camera. There is no definitive list of what works or not. Ports are developed and tested by end users who actually have those cameras. You are encouraged to read the wiki page and development thread for the particular camera you are interested in, but there is no guarantee that every issue will be mentioned.