Hi,
I am a real fan of IoTA and its tangle, But I cant think of any inherent cons the Tangle has the block chain. The notion scares me because that means that the block chain has no valid existence (which I don’t think is true!). To help IoTA grow I think it is important to talk about its weak points as well.
Pros:
no miners!!!
free transactions
truly distributed (no miners!)
enables micro transactions
scale-able transactions count increase -> transaction time decrease
Cons: