Once you burn the ISO to the DVD and boot, you'll get something called a Linux Live environment.
On the desktop there will be an Icon that says something to the affect of "Install Linux" it may say install Mint Mate on this computer or something else entirely. Just click it, step through the first screen or two and then choose to erase everything and install Linux. BEWARE that, that will wipe your drive so....... conduct yourself accordingly.
As far as being "faster" or "better" it's not exactly apples to apples so it's not for me to say.
Just thought it might be fun for you to take a look at and maybe see what you think.
And some of the more recent distros are getting bigger and seem to have a bit more overhead...