Youngest son already knew where he wanted to go and intended to firm as soon as he got an offer, unconditional or not. What put the cat among the pigeons and caused him a lot of stress was not one but 3 unconditional offers including one from his favourite university. The reason for the quandary and angst was his speculative application to an RG uni, one he thought he had no real hope at getting an offer from because of his educational history and which was also an unconditional (they were also the fastest responders with a personal email from the senior lecturer that most certainly massaged youngest's ego but also added to his angst and indecision)
He was very very tempted for a while to change his long held choice to the RG uni, just so he could prove to his doubters that he was good enough (long story which includes being written off pre GCSE due to his disabilities) but in the end after a lot of soul searching and research into the pros and cons of each course and university, location, ease of travel etc, firmed his original favourite.
For him, the unconditional offers spurred him on. He didn't just want to have the offer in the bag but he also wanted to prove he was good enough for it and to be going to university. He could do that without the stress, he knew where he was going, that it was a certainty and it gave him a chance to really show what he could do unencumbered by all the pressure and stress.
By results day, he was not only the top student in his year group during lessons at college but also for his results.