Okay, here's the skinny. I started a thread on here too. I got one and was like "WTF?" when it came --looks JUST LIKE a 3G trigger. NOT like what Brownell's has pictured, just a heads up! Pictured is your average single stage and that's not how it's made. Haven't really shot it though, I pre-ordered it before the divorce and it finally came a month or so ago. I installed it in an SBR lower I want to register (when my ex is off my trust).
So the only difference between the 3G and the SSP is that the 3G "bumps" the hammer on release (similar to a typical 2 stage) but the SSP doesn't. It's a crisp, clean let off. If you aren't a trigger snob, and I mean a big one (and if you don't own a 3G) you're not gonna be able to tell the difference.
If you are, and if you've ever tried to use the 3G from a bench with a loose grip (a habit I developed as an SDM; either lock it up tight or let it float, depending) you'll know how easy it is to make a 3G double or bump fire. Which makes sense now that I know exactly how it works and is probably what makes it such a great 3G trigger.
The SSP doesn't do this, the disconnector doesn't touch the hammer at all during release. So not sure if it'll affect bump firing with loose grips or whatever. But that is the difference, I called Geissele to ask when it came and didn't look like what I ordered and this is what we talked about.
The flat bow also has a lot to offer with 3G and SSP triggers too, if you like Geisseles but don't have a flat bow you should try one.
