Reddit reviews Russia Against Napoleon: The True Story of the Campaigns of War and Peace

Tolstoy, to put it mildly, equated Kutuzov as a complete hero as well as an equal to Napoleon as a tactician and a general. In reality, he was nowhere near Napoleon's skill and record on the battlefield, but he was still quite a skilled and charismatic commander nonetheless.

He proved himself as a pretty able commander in the Russo-Turkish War from 1806 to 1812, where he helped to encircle and destroy the Ottoman Army at the battle of the Danube. It was for this reason that the public of Russia demanded that he take command of the main Russian Army (1st and 2nd Armies) that were soon to face Napoleon, as a replacement to the highly unpopular (but still capable nonetheless) Barclay de Tolly, who insisted on retreating and preserving his army over fighting the French for key cities like Smolensk and Moscow (the former of which lost him his remaining credibility among his staff and army). Alexander I, Czar at the time, placed Kutuzov in command knowing that, should the general fail in battle against Napoleon, he would have been the choice of the people, and not the monarch, leaving him free reign to choose a new commander without blame being placed on him for the defeat.

In short, he was definitely a skilled general and was a very charismatic leader, despite his age, but he is sometimes falsely described as a "superior" to Napoleon. Even for his age, Kutuzov proved himself as one of Russia's best generals at Borodino. Despite losing the fight in the end, and suffering over 40,000 casualties, he kept his army together and managed to inflict a severe amount of casualties on the French by utilizing the pride the Russian soldiers had for making a stand and defending Moscow (which Napoleon could not draw upon, as his force was a mix of French, Dutch, German, Polish, and Italian soldiers), as well as ordering the Raevsky Redoubt and the Bagration fleches to be constructed which, despite being of poor quality, definitely made an effect during the battle.

If you want to read about the prelude to the invasion of Russia, including the battle of Borodino, the fall of Moscow, Napoleon's retreat, and all the way down the line two years later to Leipzig and the fall of Napoleon, read Russia Against Napoleon by Prof. Dominic Lieven, which is a very good read and source for the war.

EDIT: Also, to answer your last question, I believe he was. Bagration, though even more charismatic and inspiring than Kutuzov, did not have the record to back himself up, and likely would not have performed well as commander of the 1st and 2nd Armies (the 1st Army originally being under de Tolly, the 2nd under Bagration), despite his later sacrificial but effective command of the Russian left at Borodino. When de Tolly assumed overall command of the two armies after they both combined shortly after Napoleon's invasion began, as well as personal command of the first, he shared beliefs with Alexander I that the Russian Army had to avoid battle at all costs, and would draw Napoleon's supply and communication lines extremely thin. When he offered what most at the time considered a "half-assed" fight (for lack of a better term, sorry) at Smolensk, Alexander chose to relieve de Tolly and replace him with Kutuzov to avoid public embarrassment for himself (Later, at Borodino, de Tolly would command the Russian right flank and led from the front by inspiring his men to fight on, and he would later be vindicated by the Czar and the people).

Russia definitely had skilled generals in 1812, but for command of the entire army, there was no better choice than Kutuzov.