Locks that work

I just bought the Fahgettaboudit Mini d as a smaller option to the massive abus one I have been dragging around with me, and whilst it is smaller, it weighs nearly twice as much! like almost 2kg. Not sure if I would have bought it it I realised the weight. hmmm, shall i send it back?

I have a Kryptonite M18 New York Lock. It weighs getting on for three kilos. That said, I would happily leave my bike unattended even in Bethnal Green locked up with it.*

*If I used it - it's too heavy to carry around so lives ina drawer at the office.