Thanks to a post by Linda_26 I am listening to parts of King Albert's 80th birthday interview.
A few things stand out regarding his kingship and abdication. Imho he can be considered a 'reluctant king' - he did so because he felt morally obligated to become king when his brother died much earlier than everyone expected. He would have happily passed the baton on to Philippe had Philippe been a bit older when Baudouin died. And, probably the most famous quote of this interview, he would not have accepted the crown had they divorced 10 years earlier (to Paola's surprise who didn't know that until he said so during the interview).
Moreover, when he decided to abdicate, he did talk things through with his wife Paola - who had told him before that if he felt too old to be king he should step down (he cites that he was increasingly weak and hard of hearing as a reason) - but didn't truly discuss it with Philippe or any other family members. He just told Philippe a few weeks (or months) in advance: expect an abdication at some point in the near future.
When specifically asked about his relationship with 'the new king': is it good or tense? His response was 'the relationship has to be good' --> which seems a rather weird answer. That something has to be a certain way, doesn't necessarily imply that it is that way.
How does he want to be remembered? "As a man who did his duty, the best he could, and who, I hope, has done his service for his country and for the Belgians, as well as possible."