what do you mean by closed ICO ? like cindicator ?
As this ICO is now over, I can't get the difference between it and icos we call open. They do have a team and white paper, everything seems public to me. Or is the question about whether it is better to invest in an ICO or in a coin after ICO is over? In this case I would definitely prefer the second option, because at least it guarantees you that you surely will be able to sell your coin just as you bought it on some exchange.
As for Cindicator specifically, it does look really shady and is forbidden in the US as stated on their official website.