I took the plunge and did it. Downgraded the laptop to Mavericks from Yosemite. The worst thing was figuring out how to get iPhoto to work right, as the 9.6 version is not Mavericks compatible. After much consternation trying to find out how to upgrade from 8.1, I ended up clicking on the 9.6 update in the App Store, and OSX told me that wasn't compatible, but it could download a compatible update, which happens to be 9.5.1. Fortunately, I had a time machine backup from running Snow Leopard, so it wasn't a complete drag and drop files event. I'm not so fortunate with the iMac; Time Machine erased everything but 10.10 backups. I used a guide at MacWorld titled "Revert to Mavericks from Yosemite - How to" (I can't post links yet)