I have experienced it. I did hold my coins until the coins that I have drops to about a ten times below the ICO price. It was really not good to see and many got disappointed and they are yelling that these are scams, yet I was not actually considering them as one as I know their hard work. The team did their best but the market was just not so favorable for now. On the other hand there are also coins that have increased in value which I think succeeds in promoting their coins. So I think it is a matter of researching and analyzing when to sell your coins. But I would suggest if you really need it then sell it, if not so important then help the team by holding it.
It depends upon the owner of token if they want to sell or hold. You will be the one who decide to do that. If you want money its better you sell, but if you don't need it now you must be hold. it is your own descession of what is better for you.