It is all preference, you should ski on what you think is the most fun. There are benefits and drawbacks for longer or shorter skis:
Benefits of Short Skis: Easier to spin, lighter weight, easier to swtich up on rails, easier to front flip haha
Drawbacks of Short Skis: SLOWER, less stable on landings, sinks into powder.
Benefits of Long Skis: Go faster, more stable at high speeds and landing jumps, powers through crud, floats on powder
Drawbacks of Longer skis: Harder to spin and switchup, heavier, tougher to control, tougher to flex if you're light or not strong enough
Personally I would way they're too short. I ski on 178's and I'm 5'11" they're about as tall as me. The best thing is to try out different sizes and decide what YOU like best.