Do NOT use CKeditor. Use TinyMCE Advanced editor.
My website was loading unbelievably slow. I couldn't figure out what was going on after switching themes, installing cache plugins, doing everything I could. Come to find out, the CKeditor (to edit your posts), actually loads java script on your WEBSITE when people visit... I found this out with pingdom.com and yslow by yahoo (google it).
Here were my loading stats with / without CK editor
CKeditor loading time ALONE - 3.2 seconds!
score of 42 on y slow (very bad)
total site load time - 9.3 seconds on pingdom
TinyMCE Loading time - 0 seconds! (does not load to your visitors)
score of 68 on yslow (I can still improve but MUCH better than before)
total site load time - 6.9 seconds on pingdom
CKeditor is the first 5-star editor that comes up with you put in "wysiwyg" (what you see is what you get) in the wordpress plugin search. And its the only 5star editor I see. Common sense says to download it. Though this plugin is just one example, its no telling how many poor newbies (myself included cus I'm not a pro) are out their with slow loading sites because of this plugin.
I also suggest WP Super Cache over W3 total Cache, and Headspace 2 over All in one SEO. My performance and just overall functionality is much better with the other 2.
If you have any insight on faulty plugins, share the knowledge!