Leave aside the impossibility of the "guarantee". We're not being offered any more power. We are just essentially to be allowed to collect our money from ourselves in a pointlessly complicated, more costly, inefficient way (by a new kind of tax) in order that things are more "transparent". Fair enough, perhaps. Nothing wrong with responsibility. Except, as I say, for the otherwise pointless cost and complexity. It adds nothing material to anything at all.
Don't, of course, take my word for it. Read what Johann Lamont told Durham's Northern Echo newspaper:
"Ms Lamont urged people in the North-East not to believe 'propaganda' about extra powers and riches heading to Edinburgh.
[She said] 'Scotland has a fixed budget. Our choice is about how we spend it. I can understand people in the North-East hearing about the fantastic things going on in Scotland, but that other side of it is never spoken about.
Scotland will not be getting more money, it will simply be accountable for raising more of its money. I hope that dispels some myths.'"
Doesn't it just?