I always prefer to hold, as I think that an investment in something so volatile and at the same time so promising, can only be trully profitable on a longer run... there are profits to be taken on shorter term, but most projects need time to develop and at the same time we have to be pacient waiting for the bull...
Of course, there are times in which we need to be cold hearted and dump everything before the project dies... or else we'll be collecting useless coins...