As you said its taking longer and longer. They are quoting over 9 weeks now but many applications are taking longer. We were lucky my wifes 10 year visa was back in her hands in under 3 weeks in April.
Just a small correction to your post. There is no such thing as an interview when your wife visited VFS to submit the application. VFS are simply a post box to submit the application, they do not do interviews, they just forward the documents to VKV1 and report back on the decision.