Let's say you are annoyed because you can't have your sims sleep in that bed you like a lot, because of its crappy energy gain: your sim would need a lot more hours of sleep than usual, to be fully restored.
Let's also say you love that fancy expensive bed for your sim children, but those pesky brats keeps to wake up again before midnight, and when it's time to go to school they're pretty much destroyed.
If those beds are Maxis-made, you can use Lord Darcy's mod and relieve a huge part of stress, but what if you're using a custom bed? One of those typical custom beds which are amazingly luxurious, but were cloned from the pine bed or something like that, and the creator didn't mind to adjust their stats, so they're actually confortable as much as a bed with no mattress.
You can manually edit each of them in SimPE, of course. Heh. And what if you play on a Mac or/and don't want to mess around with SimPE?
Plus, the children issue (they go to bed early... and wake up too much early, too, if their bed is good enough) remains unsolved.
Let alone the weird fact that usually the value of a bed may influence the comfort, but not the amount of hours a person have to sleep, to be fully restored (if a bed is not confortable... well, you'll wake up restored in energy, but messed up in comfort, wouldn't you?).
I was sick of all this fiddling around, and I made my own mod.
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How this mod works
It's a a global mod, therefore it works the same on every neighborhood and lot.
It provides the same energy gain rate on any bed in game, regardless they're Maxis or custom, overriding their settings.
Children have a different (slower) energy gain rate, compared to adults, teens and elders.
Confort gain rate, on the other hand, is not modified: it will be the original one, built in with the bed.