I can provide an example: I have a computers store where i sell cartridge and toners, and I need to add more than just one value to the "compatibility" feature, so I can use the filter to select all the products that fits the printer.
I found two modules that can do it but I'd love to see it running under Store Manager. http://addons.prestashop.com/en/bulk-update-prestashop-modules/6356-multiple-features-add-features-without-limits.html
http://www.silbersaiten.de/prestashop/en/prestashop-modules/133-multiple-features.html