Overcoming random slowness with my home Wi-Fi and 2015 13″ Retina MacBook Pro I've had issues where the Wi-Fi seems to slow to a crawl sporadically. This only happens on my home network; I've not seen it happen anywhere else. No other devices are affected while this is happening and I can fix it by restarting the machine.

I know there are issues with Wi-Fi after upgrading to Yosemite, but this was brand new with Yosemite already installed. The Wi-Fi settings were imported through iCloud if that makes any difference.
The issues aren't with upgrading to Yosemite, they're with a component of Yosemite - every Yosemite machine runs the risk of having them. The issue's been resolved in the latest version of the OS X 10.10.4 beta, which you can download by joining the Apple beta program and following the instructions to put the beta on your computer.

Here's an article explaining more about the bug in question, if you're interested.