There is always the odd bun that will not settle down to bond, but out of the 300 odd that have gone through Hopper over the last few years there has only been one or two that didn't bond.
My Oscar was initially assumed to be un-bondable as he would launch ferociously at any female he was introduced to, to the point that we decided it wasn't fair to try him again.
A few years later we had Sea come into the rescue, and Louise had an inkiling that she might be the right temperament for Oscar.
We tried him, and after a very nervous initial meeting he fell head over heels in love with her.
We had the luxury, though, of lots of potential partners for Louise to choose from, and the experience and knowledge that Louise has around bunny behaviour.