We recently used F&B to redecorate our house but our decision was not based on colours/designer brand/etc. Their paints (modern emulsion, primer, wood) are low VOC so they: (a) don't smell, (b) are environmentally more friendly, and (c) are child safe! Little Greene are decent too but I found this paint smells ever so slightly more than F&B.
We were moving back in with a newborn, and personally I get paint fume headaches no matter how far I am from the paint so didn't want to subject my child to it.
Colour: agree that the light bounces off them... but in my experience not off every colour! Couldn't agree there is a massively perceptible difference for Dayroom Yellow or Wimborne White vs other brands, but Peignoir and some others look STUNNING.
Finish: nice and chalky in modern emulsion. Got some minor stains on walls moving furniture about. Managed to scrub off with some water and dishwashing liquid. No damage to paint.
Longevity: you should note that water based paints by their nature last less long than oil based paints. So, this paint will cost you more in the long term. But we felt we should 'put our money where our mouth is' due to the environmental impact.
The downside of F&B vs Little Greene is primers. You should be using the F&B primer on painted walls to prevent paint peeling off like vinyl. Some people/decorators don't, and then complain the paint is defective because they didn't follow the instructions. Little Greene is more straight forward because you can paint straight onto old paint with no primer (unless it's plaster... Then you should always seal or mist-coat before painting so it's not as porous).
Some decorators hate F&B based on bad experiences years ago, but I understand they have reformulated and the modern emulsion is easier to work with than the traditional one.
Anyway... Hope that helps you! Suggest you read some of the product specifications/advice sheets on the website before buying to judge whether you can be bothered. As someone said, should be repainting the entire wall not doing touch ups.