Keyboard Shortcut E What Does I Do Exactly

The 'E' hotkey passes ALL effects not just the channel tools. So you are hearing essentially raw tracks.

BMOG
I was watching CakeTV youtube on drums and he said use E to bypass the channel tool plugin. When I tried I noticed my mix sounded so much better more in your face than before.  I tested this again on a track that I have not mixed at all same results, everything got a bit louder and more in my face anyone know why?  I like the sound but I want to understand why things change that way

It has the same effect as pressing the FX button. It bypasses all the effects and processors in your project.

What you are experiencing is the tracks in their raw state before you did all that hard work mixing it. Basically only level and pan will still be working.

I, too, have sadly experienced accidentally hitting e and hearing the mix improve, realising you have spent all that time and effort basically making it worse.

Sometimes, contrary to Steve Vai, less IS more.
 
edited for spelling and grammar

Man, sometimes I wish my life had an "E" key.
 

True story: Sound on Sound magazine does a feature called "Mix Rescue" where the editors go visit someone and improve their mix. Usually the first thing they do is bypass all the plug-ins to hear what exactly the raw tracks are doing. Once the musician who did the recording went to get tea for everyone, and they bypassed the plug-ins while he was out of the room. When he came back, he said "Wow, what did you do? It sounds so much better already!"
 

SPAN is a nice tool that can be placed where you need it. It is not in house, but useful and free. In addition to meters you can also monitor the spectrum and overlay channels in one display.