In the old days, doing a clean install was pretty much required for a major Mac OS X 10.x release. Is that still the case? Or should this graybeard let go of his old ways?
The MacBook in question works well. The hard disk gets high marks from Disk Utility
app checks. Both a Time Machine and a full clone of the disk will be in place, each on their own external hard disk.
Going from Mountain Lion to Yosemite in this upgrade. Should I try simply running the Yosemite installer as being suggested by the App Store app?