Re: Flat triggers...
I use the SD-E in my PWS MK214 as well as in my 20" White Oak DI gun. Both triggers are amazingly crisp... with a very nice first stage. I like the flat trigger shoe, because it allows me to to get a nice reference point, at the lower half of the trigger for the best possible mechanical advantage.
The first stage is soft, but noticeable... allowing you to "stage" the trigger, getting your alignment and breath under control, and then you can break the shot cleanly. I like the reset on it as well... because it resets "past" the first / second stage, allowing me to feel a wee bit of slack again.
They take a few rounds to get used to... but, the more you use them, the more you will LOVE them.
Two stage triggers are not everyone's cup of tea. I happen to like them, for my style of shooting. I run SSA triggers in all of my carbines, and the SD-E in my precision rigs.
Now that I have been shooting GA triggers, I just can't get on with anything else. The flat trigger shoe is designed to provide a very nice finger purchase, and give maximum mechanical advantage because you can reference your trigger finger lower on the shoe...
I think you will find that they are very pleasant to use... give it a try. You will not be disappointed.
Cheers,
DMack