I just did the new update to Lightroom CC and it is complete garbage! I am running a MacBook Pro (15-inch, Early 2011) with 16gb memory and a 480gb SSD running El Capitan and it continues to crash and lag. It is actually completely unusable and I have deadlines!!! anyone have suggestions?
Since you don't state the exact version number, we'll have to guess (which sometimes produces the wrong advice)
You might want to try rolling back to Lightroom 6.1.1
Thank-you for your advice. I just uninstalled and reinstalled the newer version and it seems to be working well now.