Could the recounting of a single day provide enough insight to fill a whole book and retain your interest? Absolutely!!!
Great beginning: opening pages list names, occupations, and dates (better than at the back of the book). The author explains how he got the details without interviewing either Gorbachev or Yeltsin. He explains his family connections and why he accepted/rejected verbal recollections by people present that day. I'm convinced he is close to the actual events which painted a movie in my mind that I couldn't stop watching. I have never read some of these details anywhere else.
P.10 Gorbachev repeated to foreign dignitaries an anecdote against himself "about a man in along line for vodka who leaves in frustration, telling everyone he is going to the Kremlin to shoot Gorbachev, only to return later complaining, 'There's a longer line there.'"
P.11 Yeltsin will "never again have to negotiate with Gorbachev, endure his windy lectures, put up with his criticisms, take lashings from his profane tongue. Gorbachev the charming and sophisticated world statesman can turn the air blue with his profanity. Yeltsin, the hard-drinking, backwoods Siberian, regarded as a buffoon by many in international circles, never uses swear words and intensely dislikes those who do."
P.18 "It was a society pervaded by cynicism. Many people joked that they pretended to work and the government pretended to pay them, and that the four most serious problems facing agriculture were spring, summer, autumn, and winter."
P.37 Yeltsin "joined lines at food stores to see for himself how people were treated. Unrecognized once in a meat shop, he ordered a cut of veal, knowing that a supply had just been delivered. Told there was none available, he charged behind the counter and found it being passed out through a back window. He had the management dismissed."
P.45 The Soviet ambassador to the US had repeated the lies of the conspirators that Gorbachev was ill when the coup was going on. He knew he would be replaced, so on the last day "with caviar, sturgeon, champagne, and vodka, the Soviet embassy in Washington goes down like the Titanic. 'Enjoy yourselves,' Komplektov tells the 400 guests. 'This is the way we celebrate a grand occasion'. Afterwards the red flag is lowered, and the Russian colors are raised in its place."
P.212 Gorbachev gave Yeltsin 1000-2000 secret files covering criminal actions (including terrorism) committed by USSR leaders from Lenin to the present. "There was one document they should inspect first, he said when he resumed his seat. He began reading the contents to his two companions. It was a memo, dated March 5, 1940 from Lavrenty Beria head of Stalin's secret police, the NKVD, which recommended the execution of 25,700 Polish prisoners in Katyn Forest near Smolensk. Written on it in Stalin's blue pencil were the words, 'Resolution of the Politburo' and the signatures of Stalin, Molotov, Mikoyan, and Voroshilov."
Depending on your interests in stories about the people, behind the scenes plots, human interest stories, false news reports, etc you are in for an entertaining eye opener. Enjoy.