Signature campaign for sure is the most trusted, when rewards are escrowed. With Altcoin bounty campaign it is different, to check if project is trusted, you have to make your own research about dev team and whitepaper.
According to many other answers, i think mostly many are preferring only signature campaign when compared to Cloud mining. So the right choice we have is to choose the right signature campaign to be paid at end of the Campaign.
I think that many more scams are among cloud mining services. In my opinion 90% or more of cloud mining services are scams, while among signatures campaigns, scams are at most 20% ... maybe 30%
And it is very difficult to distinguish a proven cloud site pay. While the signature requires patience because the campaign lasts 2 months or more. besides the signature campaign requires a high rank account, while merit makes it difficult for us all.
nothing was easy.