We rolled out an update for a large group of users. After 3 weeks I can report that we have no major issues and only very few questions/issues regarding MicroStation V8i SS4, compared to SS2. Almost all addons/tools running inside or around MicroStation work with no change.
A side info: Our tests evaluated SS2 and SS4 on Windows 10. Both had no detectable issues related to that Windows Version.
Another info: We removed VBA components from installation because IT found a Security Vulnerability in VBA 6.x that was included in SS2. We decided to avoid such a risk by removing it in SS4.