I have that Walmart Gerber boxcutter. Costs about $10. Really not bad. Very compact and pocketable linerlock.




I've since replaced the blade retaining screw with one slightly longer, which allows easier one handed opening.

I find that some utility blades aren't very good and some are quite good. However, it's sometimes to track down brands/manufacturers. In addition, they are usually very thin and tend to get much abuse. The result may make it seem that they are poorer quality than they really are. They are sharpenable, though, even if they are disposable, and I have occasionally sharpened them to find how feasible it would be.