andybach – you don’t sound like somebody who’s only in it for the cushty lifestyle (often a myth anyway IME!). Seems you enjoy getting out and seeing the places you live in rather than seeking out other ex pats in faux Irish bars, so I would go for it. If you don’t you could find yourself feeling bored with the UK anyway…..
You’ll know best whether to continue with shorter assignments or go for something long(er) term.
I’ve found it’s easy to pick up again with real friends, and family are family regardless of where you are. Good luck and enjoy yourself whatever you choose.