Spartan w/ EDGE engine wasn't as easy to enable as the instructions make it sound, maybe because I was testing it VMware?
I had to do this first since typing about:flags in the address bar only brought up the Bing search engine.
1. Run a browser test so you can see the improvement (if any), I used http://www.speed-battle.com
(sadly after the tweaks so I have no results for before)
2. Press F12 to open a developers box @ the bottom of IE11
3. Change the 11 (default) to EDGE... its at top of the box near the right side.
4. restart IE11
5. Enter "about:flags" & hit enter.
6. Make your changes per link/post & apply changes.
My Spartan/EDGE test results in VMWare workstation 11