Still some problem exists around manual partitioning, and I'm going to report them one by one: please look at the following image, taken immediately after entering partition editor:

What you can see here is a discrepancy between partition as reported from partition editor and as reported from gpart.
How I went there:
Doing testing I first installed GhostBSD on MBR partition table, that was ada0s1a as root filesystem and ada0s1b as swap, then I decided to test a dual boot install, so I installed ReactOS, deleting the original partition which was detected as type 165 and creating a small 4 GB partition.
After that I went again to boot GhostBSD to try the dual boot installation.
Must be noted that before to install ReactOS, I had zeroed the first MB of /dev/ada0.
The output as shown from partition editor is puzzling me as I do not understand where it come from, especially considering that output from gpart look correct.
While it doesn't seem to be a problem for itself, I though I should report it.
(manual installation failed, but I will report the details in a upcoming post).