Dying to get off Chrome but FF has been giving me soso performance on 2015 MBP. Video playback is iffy and battery usage is terrible =/
Excessive JS usage is probably the culprit behind the move to Chrome. A number of popular sites are so packed with JS that using Chrome is the only way for normal users to achieve reasonable performance.
If the page actually does anything on top of that the problem grows quickly.
Are we really saying that Chrome is just more efficient at wasting CPU cycles to show adverts?