I can only speak for my own experience, but I have yet to see brittleness or yellowing with a CA finish. And it's most definitely not cheap. Compare the cost of ANY auto clear to ANY reputable brand CA & see which costs the most, ounce for ounce, gallon for gallon. As KJ & Chris did mention, CA puts off some nasty fumes. Comparing it to auto clear, however, is not exactly fair. Auto clear will kill you. CA will not, or at least according to the MSDS
http://www.co.vermilion.il.us/MSDS/Tech Services/Loctite Super Glue.pdf. That said, proper ventilation is needed to be comfortable. I built a bench top finishing/sanding station with downdraft board immediately behind the sanding lathe. Not only does it collect all fumes, but also sucks away sanding dust. It has its own dust collector to pull the draft. The lathe is variable speed DC. Everything about the set-up is designed around a CA finish. Nothing about the system, including the CA, is cheap.
The system actually replaced my auto clear booth. For that I had a sealed booth with filtered downdraft to pull away fumes & over spray. There was a gear reduction DC motor that slowly spun the cue while I sprayed it. It was as safe as any other auto clear finishing booth I have seen in any other makers' shops, and it worked great. I finished many, many cues that way. My wife got pregnant & I was afraid that I would inadvertently compromise somebody's health, so I researched every imaginable finish, experimented with many, and in the end took a serious approach to CA. I did so based on MSDS's, ease of use, and quality of end product. Simply put, my CA finishes are on par with any other finish I have used, except way less dangerous to execute. I will not shave years from my life or endanger others around me for the purpose of a pool cue.
I actually find it hard to believe the wives tales & nay saying surrounding CA finishes. Perhaps before my time CA wasn't the quality it is today, or perhaps the naysayers didn't give enough effort in their experiments. Granted I am not using cheap, thin CA and applying it with paper towels in my back bedroom. I use quality stuff in a controlled environment that I designed specifically for finishing a cue. I used to keep an old sneaky around the shop that I had finished with CA. I'd let anybody whack it hard as they could with a shaft dowel, and never did that finish chip or crack or bubble.
I'm not here to say that CA is a better finish than anything else. I'm only here to defend it as a viable finish IN MY SHOP, with my own name behind my statements. So long as the finish is smooth, shiny, and durable, does it matter what it is? Should I or the cues I make be judged by the finish I choose, or rather by the end result? I have cues that sell for many thousands of dollars that have been finished with CA, auto clear, UV, and epoxy. Nobody knows the difference because they are all clear, clean, shiny, and tough. For me the decision was 100% health related, not cost. If that is a negative then I will
live with it.