An installation of an OS without GUI can be as good or better than GUI installation.
Here is why.
Well, suse 8.2's GUI installation was very impressive. As long as it works...
But still, I think that without GUI is easier to make an OS really customised.
I can't really tell which is better text or graphical. Some graphic installation is very annoying cause you can't really do much but install what the OS wants you to; some text base installation also can be annoying when it's not explained well.