I've been using it for a while now. The only bad thing is that it lacks some features within the GUI such as importing/rescaning the blockchain, but overall it's great.
I think it's safe to say that you can use it for cold storage without any worries, it's just as safe as the CLI version.
Hi, could you please post a screenshot and a link to this wallet, if you feel like it? It sounds interesting. Is it an official GUI made by the "core developers" of the Monero project?
It sure has been a long time in the making and that's fine.
This is it, correct? I'm going to have a look at it, although I don't own any XMR at this point.