I have the Curved Aluminum Apex kit with the 5lb trigger spring installed on my 9c. It makes the gun and trigger pull feel perfect, way smoother pull, less travel, more solid feeling reset, and it looks fantastic.

I have about 250 rounds through mine with the 5lb spring and I use it as my EDC gun, I am not worried at all about the lighter pull weight.

If you end up with the flat faced trigger, it brings the trigger pull weight down 1lb. Because the trigger is flat, and slight farther from your hand, it creates more leverage making it easier to pull. (I spoke with Apex on the phone before ordering).

So stick with the curved aluminum or polymer trigger enhancement kit.

It is worth its weight in gold.

-B

Here is the link to the kit I have

Details

Here is My EDC with the "blue line series" aluminum trigger kit.