I am on roughly the same page as @Arbutus. I bought a trial membership first and was so blown away by the time savings and the quality of the research, that I popped for the annual subscription.
I love that it will write a full report and give citations for the sources so I can check them as I feel so fit. I wish I had found research material so easily 50 years ago.
Yes, for me anyway, it's worth the annual fee. What is the rest of my life worth? Why waste a single moment of that time researching things that Gemini can do for me? I'm also pretty darn good at researching things. But I confess that I'm not that good compared to Gemini Pro. It's amazing. Not much else to say.