Got a new iMac and installed Logos. It took over a day to download, install and index. Then I did a complete restore from another Apple computer. [I needed some other files on the new computer.]
Using 'Time Machine' I did a transfer from my Mac laptop to a new iMac desktop. The backup from the laptop took little time and the install on the desktop took almost no time at all. Now the amazing thing - Logos seemed to already be indexed. I waited a LONG time to take the leap into the Mac-World but a while back I did and am still discovering benefits. I don't understand why, but it did work.