I think I know what you're talking about. I have two AR 15's that are almost exactly the same setup.
The two differences between them are the twist rates and the triggers, otherwise same everything. One has a Timmney single stage, the other is a Geissele SSA. They are two very different beasts. And I like them both very much. They are not free-floating precision rigs. My first shots with the single stage triggers are usually faster on target Than the Geissele triggers, when going from the slung rifle position. Because I don't have that first stage take up.
I am more precise though with the Geissele because the second stage breaks so lightly, i'm probably just as precise with the Timney, but the Geissele is actually faster for precision follow up shots.
And it can be a little "odd" to go from one trigger to the next, especially in the same range session, but you get used to it. It becomes automatic pretty quickly.
I don't have SSA-E, but for my next precision rig I will. The high speed DMR I use in my SASS was a bitch to get adjusted just right, took 1/2 a day, and I don't know if the faster lock time really helped that much as I'm a firm believer in follow through. But it is an AWESOME trigger!!
What type of AR are you running?
I wouldn't want the SSA-E on a combat or hunting type rifle, it feels to light to me. But then maybe that's just me. I like to be prone or on a bench with that one.