I've got to say something that will likely upset at least one person, but I really can't stand the well know brand names anymore, like Dulux.
The cost is huge, but the performance increase isn't.
I bought £1-2 hundred pounds worth of their Light and Space recently for the house because the sunlight doesn't get inside some bits very well.
It does help! I can certainly see a difference.
But it fades once the inevitable dust and mucky hand scuffs build up, which happened in less than a year in my case; a room I just painted with B&Q's £9.99 big tubs looks as bright as the areas I did 6 months ago with the Light and Space.
Also, the cost of the stuff is unreal compared to the gain. It's about £30 - 45 for a 5l can?
Now, I just go straight to the stores own brand big tubs and apply an extra layer if it's not as pure / solid as I want it. Dulux has never done that for me either, the one coats are never one coat to a layer that doesn't get better without another coat.
Sorry guys! I know, they are nice paints, it's just the cost doesn't match the performance for me.
I've entirely stopped using glosses in the house. It's getting urethane or epoxy if it needs that kind of finish; e.g. floors, worksurfaces / walls in the garage, sanded floors etc.
I DO use branded paints for specific tasks, like covering moisture stains where a normal emulsion hasn't got a hope in hell. I just bought a can of ICI stain block. But the price tag on the Dulux emulsions is just way too much in my opinion.