I rented one in SW London for years storing my weekend toy. It was a 5 min walk, 3 min cycle from my house. In hindsight it meant I used my car less and I was constantly worried about security, as the lockup area wasn’t overlooked and the forecourt unlit. I just hoped there were other easier targets out there.
I know of other, less secure garages that were broken in to. A number of tradesmen used the garages to store stuff and there was a lot of sharp debris on the floor, though luckily I don’t recall ever getting a puncture, something to bear in mind.
I have car OCD and as a weekend toy my car would have been liable to the bumps and scrapes of on street parking, however the cost of repairs would have been less than my rental outgoings over the years. What is the cost of hassle of repairs to you.....?
At the end of the day I think everyone’s situation is unique. Weigh up convenience, access, cost and security and go from there. Don’t lock yourself in contract for too long a time in case it doesn’t work out.