Best Lock to Buy?

I hardly see the Master Lock Street Cuff mentioned.

Is this model or the more heavy duty version any good?

this is the lock that i have, however i very rarely lock my bike up in central london or high teeleefing zones.
i think its physical presence is a deterent to your average spun out druggie and the sight of what looks like large hand cuffs probably doesnt do anything for their ever decreasing buzz.
anyway when i had a garage broken into the policeman who came to do whatever it was he did said something that made so much sense. words to the effect of 'the thief unless they know whats inside is going to go for the easiest garage they can break into'.
now relate that to locks and accept that all locks can be broken the only deterent is the lock that looks imposing enough to have them believe its going to take a while to buss. part of the thiefs plan is not getting caught and they longer they have to wrestle with your lock the greater the chance they have of getting caught.

these are just my thoughts,any reliance upon any of the above shall be at your sole risk.