I have heard and read about it but have not used it. All of my Glocks run the Glock minus connector, sold as their former 3.5 unit. I also do some other things to get my trigger pull weight and feel to where I want it.
Some of the guys on glocktalk.com, which you have probably seen, are running the Ghost Evo Elite connector so if you have not been there, check it out. Gen4's usually take a little more work to get a good trigger, mostly due to the "bump" on the side of the trigger bar safety block cam. You can swap out that trigger bar for a gen4 unit IF you are having some issues with it (I've done this on a couple of mine).
My goal is to have around a 5 pound trigger with a decent break, for Glock, and a smooth stage one pull. My two primary carry Glocks have this and both are gen4's.
Sorry for the rambling and no experience with the Ghost Evo Elite to help you with your question. Oh, and as far as modifying your trigger and legal issues with this, that is going to depend upon the state in which you live. It is NOT a nationwide issue.