As mentioned already, the SR9c is more comparable to the M&P9c and the Shield is more comparable to the LC9. Comparing the SR9c to a Shield is Apples & Oranges.

I had the SR9c for a while and when I was shopping for Compact Double-Stacks, I much preferred the trigger of the SR9c to that of the M&P9c.

In Subcompact Single-Stacks, The LC9 trigger is a true DAO (long revolver style pull), as opposed to the Shield's Striker Fire trigger. I preferred the PF-9's trigger over the LC9's and (obviously) prefer the Shield's trigger over both.

I can pocket carry my Shield. This was the main reason I bought it. If the Shield is too large to pocket carry, one needs to weigh the age old Comfort vs. More rounds debate to decide if you want to go with a compact Double-Stack or a subcompact Single.