The Sky 6 does have a soft copy of the manual in the CD package.
Since you have had The Sky 6, no need for The Sky 5 manual although functionally both versions are equal.
The Sky 6 differs from Version 5 mostly in cosmetic display + T-Point software. If you don't have T-Point working with a rigid permanent mount as in a roofed observatory, using the Sky 5 is as good as The Sky 6.