I can't say I've every been happy with AMPs service levels. Sometimes it's okay, quite often it's not. I don't recall it ever being great, they are a difficult lender to deal with.
That said, they do have their niche. They tend to be a lender that you go to for very specific reasons and there's probably not many alternatives.
Right now though, I wouldn't be too concerned about a 24 delay in loading a property valuation. I've experienced far worse with other lenders on this same thing. At the moment there's a lot of infrastructure related problems as a result of the weather last week in Sydney, quite a few lenders are experiencing delays. The cause of these delays is probably solved by now but the lenders are still playing catch up.