Anyone renewed their permanent UK visa recently?

I'm Australian, I've got UK Indefinite Leave to remain and I've just got a new Aus passport.... which means forking out £500 to the Home Office to get a new UK stamp put in my new passport

If anyone reading this has this sort of stamp renewed, was the process straightforward?

Did they ask for documentation for previous years proving you have been living in the UK? Are they only interested in current documents? What do they want?? People on http://www.expats.com told me to call the Home Office. I called up the Home Office twice now (to find out what I needed to do and then to make an appointment) and I got a different story each time.