I’ve had both. IMO, the SP-01 Shadows and 75 Shadow needed much more work to improve the trigger pull. My Shadow 1’s were customized by CZ Custom and they did a really nice job polishing, spring changes, hammer/sear tuning, and reach reduction. However compared to my Shadow 2, all I had to do was re-spring it and a DIY polish to get a comparable DA/SA trigger pull.
The Shadow 2 fits my hand better, especially how the beavertail sits in the web of my hand. More comfortable over a long day at the range. The added weight is nice to keep it flat shooting.