Is it worth getting a 900 over a 650? Fulls. Largely commuting Balmain, want to join group rides

Hey, I've been out of riding for a while and tbh I wasn't riding that long before that. I rode a CB400 during my Ls and loved it, but admittedly got bored. Then I jumped to a XSR900 which was amazing - looked and sounded great - but tbh was too much bike for me. I was pootling round the eastern suburbs at 50, and when I did ride to the national park I didn't have the confidence to push it even 50%

I'm now looking to get back into it and have been eyeing the Z650RS, it looks gorgeous. But I don't want to buy a bike that I will get bored of, so obviously the Z900 is an option. I just don't know if I really need it. I'm not a speed demon, I just love the freedom a bike provides.

I know the prevailing thought is SELL YOUR Ls BIKE IMMEDIATELY AND GET A LITRE, but what do you all think?