However, I just started the installation again (which is really fast and takes just a few minutes) but I had yet another problem: When trying to setup pkgin, that failed because it said it couldn't download something from "http://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/amd64/7.0_RC3/". In fact, that directory doesn't exist. I realised that there is path to "7.0" (without the "_RC3") and changed the path accordingly. The installer warned me that at least one package was build for RC 2 rather than RC 3 but I decided to accept this and the installation went fine.
After installing the "usual suspicous" packages (bash, nano), I installed XFCE and was very delighted that it made a huge jump from version 4.6 in NetBSD 6 to 4.12 in NetBSD 7. A first trial was a little bit disappointing: The performance was quite poor, the mouse pointer disappeared and appeared again continuously and there was a background with vertical black and white stripes in contrast to what was set up in the settings dialog.
Figure 1: XFCE 4.12 in NetBSD 7 RC 3 with wrong background
To demonstrate this, I made a short, two minutes video.
If I have the change to do it, I will try installating NetBSD 7 RC 3 inside VirtualBox and see if it performs better there.