Hi @xwing, thanks for the feedback. In the past this issue has been due to firewall issues, so please try temporarily turning off any third-party firewalls to see if that fixes the issue. The size of your library is definitely not the issue there.
Unfortunately the old importer had many, many issues, so though it did work well for a lot of people, it was glitchy and did not work well over all, hence our decision to change to this method.