Can I ask you to explain better what do you mean when you are saying multiSig cold storage? I have seen bitrated, maybe you can register on it and after put your profile link here.
No! I don't like such sites. They create private keys for us which isn't good idea IMHO.
I use multisig cold storage(2-of-3) which is spread over a few devices which I own. So it give super security. The user who want their funds to be escrowed doesn't want to do anything other than sending me the funds and do the deal, i.e. they don't want to install or register any thing.