Always install Update 4 after SP1, not before. Use Siemens’ SIMATIC Automation Tool to verify the installation integrity.
Only if you are locked into the V13 ecosystem. If you have any choice, go to V15.1. But if you must use V13, Update 4 is non-negotiable – running anything earlier is professional negligence.
Overall Rating: ⭐⭐⭐⭐ (4/5) Best for: Engineers working on legacy S7-1200/1500 projects who need stability without migrating to V14+. The "Better" Factor: What Improved? If you used the original TIA Portal V13 (or SP1 without updates), you know the pain: random crashes, slow cross-references, and HMI compilation errors. Update 4 was the patch that finally made V13 SP1 reliable.