I do think you can have too much chain and too much anchor weight. When it becomes unmanageable and is no longer providing additional necessary holding then you have too much. I feel good with a 25lb Manson Supreme and 30' of chain on my anchor rode on a ~8000lb 28' boat. However I'm not anchoring and leaving it alone for months at a time like Aaron...if I were I'd upsize. I'm typically on the boat while it is anchored.
I like the Manson Supreme a lot. It's expensive, but it sets (and resets) quickly. I have a Fortress as my lunch hook/secondary anchor and it doesn't set as nicely.
Note that you can also back down the anchor by sailing backwards by pushing the main sail out on the boom. There is nothing more peaceful than dropping and leaving anchor by wind and leaving the engine turned off. Of course this works best in large open anchorages.
Don Casey has a different take on anchor scope in this article that is worth considering:
Ground Rules: Anchoring in Three Dimensions | Sail Magazine
In Seattle we have much larger tidal swings than on the Chesapeake, so I've never had the experience of anchoring in 7' of water. Last Sunday we had >15' swings, so anchoring in 7' of water would mean you'd be in 22' of water later on. That makes you think a lot about scope.
I usually seem to anchor in 20-40' of water and go for a 5:1 scope. My rode is 300' total, so I can anchor in up to 60' of water with that scope.