Lets see if we can find Davis's opinion of Forrest. It seems Forrest was a for lack of a better word a victim of Bragg. A better Question might be What if Forrest was given command instead of Bragg?
Murfreesboro proved to be just the first of many victories Forrest would win; he remained undefeated in battle until the final days of the war, when he faced overwhelming numbers. But he and Bragg could not get along, and the Confederate high command did not realize the degree of Forrest's talent until far too late in the war. In their postwar writings, both Confederate President Jefferson Davis and General Robert E. Lee lamented this oversight.
http://www.thelatinlibrary.com/chron/civilwarnotes/forrest.html
Mobile cavalry warfare
In December 1862, Forrest's veteran troopers were reassigned by Bragg to another officer, against his protest, and he was forced to recruit a new brigade, this one composed of about 2,000 inexperienced recruits, most of whom lacked even weapons with which to fight. Again, Bragg ordered a raid, this one into west Tennessee to disrupt the communications of the Union forces under General Grant, threatening the city of Vicksburg, Mississippi.
Forrest protested that to send these untrained men behind enemy lines was suicidal, but Bragg insisted, and Forrest obeyed his orders. On the ensuing raid, he again showed his brilliance, leading thousands of Union soldiers in west Tennessee on a "wild goose chase" trying to locate his fast-moving forces. Forrest never stayed in one place long enough to be located, raided as far north as the banks of the Ohio River in southwest Kentucky, and came back to his base in Mississippi with more men than he had started with, and all of them fully armed with captured Union weapons. Grant was forced to revise and delay the strategy of his Vicksburg Campaign significantly.
Forrest continued to lead his men in smaller-scale operations until April of 1863, when the Confederate army dispatched him into the backcountry of northern Alabama and west Georgia to deal with an attack of 3,000 Union cavalrymen under the command of Col. Abel Streight. Streight had orders to cut the Confederate railroad south of Chattanooga, Tennessee, which would have cut off Bragg's supply line and forced him to retreat into Georgia. Forrest chased Streight's men for 16 days, harassing them all the way, until Streight's lone objective became simply to escape his relentless pursuer. Finally, on May 3, Forrest caught up with Streight at Rome, Georgia, and took 1,700 prisoners.
Forrest served with the main army at the Battle of Chickamauga (September 1820, 1863), where he pursued the retreating Union army and took hundreds of prisoners. Like several others under Bragg's command, he urged an immediate follow-up attack to recapture Chattanooga, which had fallen a few weeks before. Bragg failed to do so, and not long after, Forrest and Bragg had a confrontation (including death threats against Bragg) that resulted in Forrest's re-assignment to an independent command in Mississippi.