I have a Hiplok Spin HERE which i use for work and locking in town when i pop to the shops. Neither are particularly high risk, work i can see my bike from my office window and in town its always in a visible public place (and not left for very long).
Less than a Kg, combi lock and surprisingly robust means its very practical to take and use. I’ve had bigger locks that i’ve been reluctant to take as it’s too bulky so i didnt end up using the bike. The chain is solid and so is the locking mechanism, i dont worry about the bike when i leave it for a short time. Comfortable to wear as well, considering.
I do have a big D lock that i occasionally use if i need to leave the bike in town for a long time, but that goes in a panier bag.