Apart from the fact that I could probably retire at 55....
Probably not in fact. Anyone who has 55 as the retirement date in their contract
currently will still be able to go then, although anyone joining after 2006 (when you would almost certainly be) is unlikely to have that option. Obviously, you can leave when you like but if you're thinking pension then 55 is increasingly unlikely.
I'll let others discuss the pros and cons, suffice to say I've not married and the job has been a significant factor.