Can't comment on hand-brushing, but it does need to be thinned with water for air brushing, so should be the right consistency for hand-brushing.
They are cheap enough to buy just one to get the feel of them, & the 'cubes' have a flip-top lid which can be used as a pallette.
Not surprisingly, since RoG are, erm... German, their colour range is especially good for BundesWehr colours, esp those '70's BW OliveGreen.