Both rate 3/5 for grooming and the work could not be less alike. The rough-coated Griffon needs hand-stripping or regular clipping and a tidy of the beard and facial furnishings, which for most owners means a groomer every couple of months. The smooth-coated variety needs almost nothing. Shedding is 2/5 either way.
The Akita sheds at 5/5, blowing a dense double coat in clumps twice a year, and needs an undercoat rake and a bin bag through those weeks. Between blows it is undemanding. The coat should never be clipped, since it insulates against heat as well as cold.
On money the Griffon is cheaper to run at $80–$150 a month against $110–$240, and $1,100–$2,300 against $1,700–$3,200 in the first year. Weight explains most of that.
The number to be careful with is veterinary. Airway surgery, an MRI for suspected syringomyelia, and repeated corneal treatment are all realistic in a Griffon's life, and any one of them will erase several years of the difference in food.