It depends on what I use it for.

When I used to cut a lot of rope, I had a blade that wouldn't cleanly slice through a sheet of paper but would put the hurting on some braided rope. I considered it more then adequately sharp for the job.

The knives I use for splitting bones on wild game are generally the same way. Don't know a way to test them other then rip a few rib cages with em and see what edges work best.

The knives I use for skinning are kept as sharp as possible without stropping.

My general utility/EDC knives are kept just sharp enough to do all my daily tasks without extra effort required by dull blades. As soon as I notice they are getting to the point that they -need- sharpened (usually a few nicks in the blade, and generally just dull) I'll sharpen them up enough to slice paper and let them be for another 4 to 6 months. Rinse repeat.

The only knives I obsess over are my kitchen knives. I don't make them razor sharp, but they receive a touch up on a -very- regular interval.