I guess so. My favorite problem with singletons is testability. How can you properly mock/observe/etc it inside a test case, if lots of test-cases are executed

I guess so. My favorite problem with singletons is testability. How can you properly mock/observe/etc it inside a test case, if lots of test-cases are executed in parallel. With a real global object it can be tricky. But if the object is not global because an IOC container might still create a fresh one per test, it wouldn't be an issue.