Gabrie,
Glad to hear you got it resolved.
Normally it should not take that long to install though.
The iMac you have is a late 2012 model right?
I'm asking because if it is an older model, then the CPU might not be supported, which could explain it being slow.
Is the guest OS itself still slow after the installation?
If it is a late 2012 model, then what kind of harddisk is in it?
--
Wil