I've done several hundred pens with CA finish, and it seems durable as long as it's applied within the product's shelf life. Pricing on one 8 oz. bottle of CA is less than four 2 oz. bottles--but not when you have to throw 3 ounces away. Flexible CA is helpful when using as a wood finish. The CA's i've liked best are Mercury Flex and Glu Boost, preferably the latter. Both apply much better when used with their own accelerator, and while the fumes are still not good, they are not nearly as obnoxious as i've found some of the more popular CA's to be.
In additions to pens, i've liked CA on bottle stoppers, openers, etc. There's a learning curve in the application, and at least 1,422 "right" ways to apply. Many great pen turners use blue paper towels as an applicator--every time i've tried it i have the paper towel flapping around stuck to the blank!!
earl