CoinDeal is not a good exchange in my opinion. They don't have a lot of reputation. I don't think it would be a good idea to go with such an exchange token for investing. In long run, you may lose the BTC you invested.
It's not clear whether this is a scam project or not consider about there was no a scam accusation for this project and some people have been saying this is a good exchange site but just take it based on the demand that has already gotten by exchange site and it seems like this is not a recommended coin to invest. i do agree about that and it's better moving to a better one.
I haven't found any scam accusations against Coindeal. I have used it for couple of times and I must admit they aren't that bad. I have some good experience in Coindeal. But if the conversation is about CDL then I might say you should have some extensive research about CDL.