I stand corrected. I could have sworn I read somewhere that David Troughton didn't want to portray his father's role.
It's always been reported as such.
It was even said back in the early-90s that he was uncomfortable with the news that he was going to be "cast" as the eighth Doctor when Virgin planned to regenerate the seventh Doctor in the NAs. Then it was said that he posed for publicity photos for Virgin, but then it turned out that the supposed photos were from A Very Peculiar Practice
and he wasn't aware that Virgin had planned for him to be the "model" for the eighth Doctor.
From all indications, however, he's enjoyed portraying the second Doctor on audio.
That being said, I know I've seen such interviews with Sean Pertwee.
What I've heard is that Sean Pertwee would like to portray the Doctor, but not
the third Doctor.
To me, he doesn't sound much like his father.