I'm perfectly content with my 1.0 without a slide safety. It has trigger work, a Talon grip applied, a Dawson tritium FS, and a blacked out factory rear. No complaints.
I bought another for my wife several years after I bought mine. Her trigger out of the box was vastly improved over what mine was. Nothing needed for hers. Seriously it was a night/day difference. Mine was a skosh over 7lbs out of the box. It now runs 4lb 2oz and hers is just enough heavier to be able to tell so maybe 4.5 to 4.7lbs?
The previous comment about there being less difference between the 1.0 and 2.0 Shields vs. the M&P FS is spot on IMO.