I know this thread is almost done but I would just like to add.
my first semi auto was a sigma.. 12lb trigger, no bells or whistles. straight forward beginner auto loader.
when acquiring my second gun I felt the differences in the trigger/ action and all the other bells n whistles.

the sigma is great for breaking into the handgun world. it lets you appreciate the simple things in life while giving you a benchmark to compare future pieces to.
if this isn't your particular cup of tea, go with the sd or m&P id go m&p if I had it to do over again. but then, i wouldn't be able to fully appreciate all that it had to offer.

oh and as for the trigger, some adapt and become better marksmen, others trade it in immediately.
but that was my first trigger I pulled, and It didn't even bother me.

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sw9ve, 24/7 pro Ds, Hs M4