Your hands hurt after cutting a piece of plastic?? I honestly and seriously don't think I have any comment to add to that... Life is not easy... so if you are complaining about cutting plastic... wow. I'm sorry, I am just a little put off guard that people would be complaining about that! I would work 13 hours a day at an Amusement Park at 18 (4 years ago) picking up garbage, cutting grass, greasing the train tracks, operating and maintaining rides, run errands, etc. For 13 hours a day, 6 days a week (closed on Mondays). My back hurt, but yet I still got the job done. And from this site, I have cut **hundreds** of cases and never had a blistering problem.
To do only five cases and complain, (just getting you aware of real life) you are REALLY not going to get anywhere. Man up. It's just a pair of freaking cutters.
You know I never responded to this, might as well now...

Work smarter not harder. And I never said my hands blistered, that was the poster above me.
There is no way I would use a Stanley razorblade! I have burned myself multiple times using my soldering iron, I can only imagine after doing multiple cases what could go wrong with a cutter knife.