What is the best interpretation to be made from Simulate max stress prediction?

Good morning, I ran stress analysis on 3 design options with 3 different convergence methods. The maximum stress results are shown in the diagram above. How to interpret it?

1: Design-3 is the best? 

2: Never trust Quick-Check (QC) and Single-Pass Adaptive (SPA)?

3: Always run Multi-Pass Adaptive (MPA)?

Thanks.

JS