I have never seen a Sheffield stand where I live, but far better than what we have. The only way to lock a bike to the ones here is to take up 5 or 6 lock points since these are designed only to lock your wheel to them. Have a ulock ? Find a sign.
I'm also a fan of the Sheldon Brown lockup strategy[1]. There's also a modified version that may be more secure[2].
[1] https://sheldonbrown.com/lock-strategy.html
[2] http://www.802bikeguy.com/2011/07/the-modified-sheldon-brown...