GoldBug: Secure Instant Messenger

I’d go with OTR for this and the website supposedly answers this. While I don’t fully understand their answer, they seem to be saying that OTR is an add-on rather than an integral part of the protocol and hence Goldbug is to be preferred over OTR.

However, there are various reasons why transport and encryption should be different things (among others: I can use the same OTR keys etc. over ICQ/XMPP/MSN and possibly even Skype). Is there an added benefit of Goldbug over OTR, such as obscuration against network-wide attackers (à la Bitmessage)? Or is their ‘decentralised’ approach the only thing going for them? – which I also get by running my own XMPP server.