I tried to reply to the above thread but "Reply" did not work. Sorry for the new discussion.
I found this re Command-L:
"sometimes the installation progress bar and time remaining indicator are wildly inaccurate when installing OS X Yosemite, but fortunately just being patient almost always resolves it.
"If you want to watch what’s going on behind the scenes, hit Command+L to bring up the installation log. This shows exactly what’s being transferred or copied, rather than relying on the inaccurate status bar."