One of the things that re-watching Father's Day highlighted for me was the different approaches RTD and Moffat tend to have towards dealing with the concept of time and time travel.
Now, for me, it's not really a "better" or "worse" thing so much as a "oh, that's kind of a neat contrast" thing.
The Fixed Point in Time Approach
In Father's Day we're introduced to one of the major themes of the RTD era - when time travelling, you can watch and experience, but you can't always interfere and change things. Even when they're horrible things. Pete's death as an ordinary person is one of the "most important things" in all of creation. When Rose changes that, she almost destroys the Earth. In The Fires of Pompeii, the Doctor and Donna have to stand back and let a whole city of people burn (and... then... cause it themselves). And then in Waters of Mars, the Doctor reaches his snapping point and goes all "Time Lord victorious" which, while AWESOME, was also... crazy and not okay and led to Adelaide suiciding herself.
RTD's approach is, in other words, psychologically focused and character driven, and while it can bring out the most selfish in people (Rose saving Pete, Ten saving Adelaide and her crew), it also brings out the best in people - think Pete sacrificing himself for the world or Adelaide killing herself to preserve the timeline. I mean, JUST TRY AND WATCH THESE EPISODES AND KEEP A DRY EYE. I DARE YOU.
The Wibbly Wobbly Timey Wimey Approach
As early as Blink (and even GitF), Moffat has taken a bit more of a flexible approach to time travel. He builds relationships on people moving in and out of each other's lives at various points in time (Ten/Reinette, Doctor/River). He hangs many of his plots on his heroes doing something because they already did it... or... will do it... or saw themselves do it already (Blink, Time Crash, the Pandorica Opens/The Big Bang).
Moffat, in contrast to RTD, often plays with time to cleverly build his plots and create a "OMG WHAT WILL HAPPEN NEXT OMG" tension. He also also has a tendency to pen relationships where one person moves in and out of another person's timeline (the Doctor and Amy, the Doctor and Reinette, River and the Doctor). In Moffat's Who, time is rarely something that's linear.
And now that I've babbled, TIME FOR SOME DISCUSSION QUESTIONS:
Do you have a favourite "fixed point in time" episode/moment? A favourite "timey wimey" moment? How hard does Father's Day punch you in the grief bone? How scary and fun was Blink when you first saw it? Can you think of any drawbacks to either of these styles? Does this ultimately say a lot about what makes Doctor Who so cool - that the "fixed point in time" stories and the "timey wimey" stories both work without contradicting each other?