We have been given the choice and we decided 'not to resuscitate' when it was my Mum. The doctor at another hospital made a decision on his own back when my Mum was first admitted 'not to resuscitate' and we got that changed, as we felt he had no right to make that decision without consultation with us and because it was, in our opinion far too soon for this. We felt at that particular time, that he wasn't giving Mum a chance to fight back.
When she was transferred to specialist unit in another hospital the doctors and nurses were superb. It was only after constant battles that we realised that nature had to take it's course and that Mum had been through enough suffering. The doctors and nurses supported us throughout our time of making the decision and although it was tough, you do have to do what is right for your loved one and not add to their suffering needlessly, through unintentional but selfish needs to keep trying everything to get your loved one better.
If the circumstances happened again, I would still chose to opt for 'no' for rescuss. There comes a point when life is no longer viable and you have to allow the mind and the physical body of the ill person to decide when life is no longer sustainable, rather than opting for artificial support that adds to suffering instead of relieving it.