I'm glad you brought this subject up. I've had full coverage on both my 2013 Like 200's since buying them new in 2013. I checked KBB and they are presently worth about a 1/2 to 2/3 less than I originally paid for them. I just called my insurance company to see what the difference would be if I only kept liability insurance. I was currently paying over $150 for each bike for full coverage. After removing the collision/comprehensive portion of my coverage, the premium was now about $68 each. That's a pretty significant difference. Hence, I decided to remove the collision/comprehensive portion of my insurance.
I guess to answer your question, it just depends on your situation. If it's your only bike and your only means of transportation, then you might want to consider that. You also have to look at your financial situation and see if you could afford to replace your bike if it was totalled/damaged. Another thing to consider is the area in which you primarily ride. Is it a high crime area? Is it a high traffic/accident area like NYC? If so, you might want to consider maintaining full coverage. You can't just look at the depreciated value of your bike.
For me, it was a no brainer. I own 5 other scooters, it's not my principal means of transportation, I live in a relatively rural, low traffic/accident/crime area, and in the event they are wrecked, I can afford to replace these scoots even without receiving the depreciated value of my Likes.