So how safe is it? I read this https://www.reddit.com/r/Bitcoin/comments/2kr1qk/coinbase_multisig_vault_not_as_secure_as_you_think/ but is it still valid?
Not secure like not secure as in a bank? Because I'm kinda looking for a bitcoin bank that can store the coins for me.
With multisig vault you control the private key though, it's 2 out of 3 needed and coinbase only carries one.
While this is partially true, remember a site or program needs to create these keys for you, if its connected to the internet someone else can always have the key. Generating the private key / address on a computer not connected to the internet and that won't ever be is the safest way to make sure the keys are truly private.