Well, I suppose that depends on your eyesight and the pace you can maintain at a film reader, and the arrangements for reproducing the film images [note taking, printer, or scanner].
If you are only interested in a specific unit, such as the 38th Arkansas and its parent commands, perhaps you can scroll through the other material quickly. I couldn't. For me, it was the microfilm that I couldn't put down.
In my case, virtually every frame of every reel was of special interest, and required either note taking, printing or scanning. I repeat, there is an immense amount of useful information in this collection. I was fortunate to have a fellow researcher loan me his personal collection of film.
After a couple of years or more, I have finally grouped my notes and transcriptions into a semi-organized arrangement of personal use information. My system [so called] arranged materials chronologically within several command groupings such as Army of the South West, Hindman's 1st Corps, McBride's command, M. M. Parsons' command, Carroll's command, Roan's various commands, Raines' command, etc. This was done for my own personal purposes and not for publication.
If you intend publication using this material, you should well note the requirements for proper crediting.
The original materials are held by Columbia University, and at their web site is a finding aid, that offers a guide to information that can be found on each reel. This may help you prioritize your search.