This bike folds down to the size of a large brief case. I can keep it inside in a convenient location that does not take much room. The bike is accessible so I can just grab it and go. Locking it up outside is not necessary since I can bring it in with me.
It rides nice and is comfortable just like a full size bike. I usually bring it in with me wherever I go, so no worries about locking, unlocking, or having the bike stolen.
I customized the bike so it turns into a small grocery cart. Grab the bike, cycle to the grocery store, fold into a pseudo-grocery cart with the Brompton Bag, buy groceries, ride home. Again, no looking for a place to lock the bike, unlock it when I leave or worry about it being stolen.
I use my Brompton mostly for commuting. I have cycled 40+ km at a time on my Brompton with no issues. It rides just as well as any full size bicycle I have ever used.
My only regret is that I did not purchase a Brompton years ago.
If you are looking for a new bike, search for Brompton on YouTube and check out some of the videos about the quality and versatility of Brompton.