If you define a "friendly turnover" as a political party succeeding to the presidency after an election rather than after some cataclysmic event such as a death or a resignation, it’s only happened three times in the 20th century: 1909, when William Howard Taft succeeded Theodore Roosevelt; in 1929, when Herbert Hoover succeeded Calvin Coolidge; and then in 1989, when George Bush succeeded Ronald Reagan. In fact, if you examine President Hoover’s memoirs, he said in just one paragraph that he decided to retain all President Coolidge’s appointees at the Assistant Secretary level because, for one thing, he knew them all.
There are certain clear advantages to having this friendly turnover of succeeding a President of your own party, and on balance it is good thing. The advantages are that there is a continuity of policy, that there is an immediate pool of appointable talent to be retained or elevated or otherwise moved around in the government, and then there are people you can leave in their positions while you conduct searches or clearances for their successors. The inevitable consequence of a friendly transition are that there will be some hurt feelings out there when the smoke clears from the transition.
It is inevitable that Presidential Personnel will be a big news story during the transition and the immediate post-inaugural period, deep into the first year of the administration. One essential element of a Presidential Personnel Office would be a full-time press person to field the calls that will come in with the body counts: "How many vacancies are still open? How many women have you selected? How many minorities are selected? How many people from Ohio have been selected?" These can occupy the day of the Director of Presidential Personnel, who has a few other things to do, such as interviewing people, attending meetings, taking calls from Senators, and all the rest.