The reason I ask is (as described in the article) I've nearly run out of RFC1918 space because of dozens of machines, gadgets and many more virtual machines. (For complicated reasons to do with the VPN routing, I cannot use 10.x).
> If I'm going to do that why wouldn't I just go straight to IPv6?
Because it is a lot more than just renumbering.
Whether or not it's a good idea depends on what you expect to get from it (anything?), how good your ISP's IPV6 support is, and how good the support of hosts you connect to is.
If whatever hosts you contact are all on IPV4 only, then you'll have to occasionally debug the 6to4/4to6/Teredo/whatever kludges that add latency and provide nothing of value compared to using an IPv4 directly.