Agreed. However, just look at the topic - "El Cap lags like Yosemite - Nothing's changed"; it implies that "El Capitan Lags for everyone". And, maybe it's just me, but it also seems a bit emotional as well.
And people have been saying that it's not true, El Capitan doesn't lag for everyone. For the poster - it does, sure. For you, your 3Gb TIFs load poorly. For a lot of people, it is lag free. For example, a lot of things I worked on in Yosemite used to lag, from Mission Control, to opening Previews - heck, even my mouse lagged from time to time in Yosemite. All of this is gone in El Capitan and the system is constantly responsive no matter what I throw at it - from running Photoshop, Painter and Zbrush to surfing or checking out Twitter with Tweetbot. The same is on my RMBP from 2013. And my Friends MBP from 2010 and iMac from 2011 works faster as well. So, no - it's not true that "nothing's changed".