You can consider cmake a tool like make and the compiler, i.e. something
which should already be existing on the system.
On most systems this is now already the case.
On basically all desktop distros this is the case now, and more and more
other programs are converting to cmake. So maybe cdrkit is the first
program you are encountering now which uses cmake for your distro, but
there will be more in the future.
If you want to avoid the build time, you can also use the binary cmake
release which you can download here: http://www.cmake.org/cmake/resources/software.html
It works on all Linux distributions (at least we don't know of any where
This still adds size, but you can save the build time for cmake.