This year I successfully grew (ya, me huh!) both Red Holland and Grey Griselle Shallot.
Red Holland: several bulbs the size of a golf ball scapes (yummy!) Taste of a yellow onion with a garlic overtone
Grey Griselle: lots of little tiny bulbs the size of garlic cloves sinks that can only be characterizes as "bark". You have to "saw" through hem. Taste of a yellow onion with a garlic overtone no scapes :'(
EXTREMELY STRONG. Can only be used in cooking. A "sliver" will cause severe pain in your sinuses and make your stomach lurch so hard you will almost puke.
Lessons learned: they like to be watered like any other plant. They like acid soil. The bulbs with more peat moss around them grew bigger.
My conclusion is that both of these are a pain in the ass to grow for the small amount of food they produce. And Both the wife and I like Yellow Onions better. So next year it is yellow onions instead!
I have my eye on "Senshu Yellow" yellow onions. They over winter and like zones 5 and 6 (I am 6c). Plus they give a half pound bulb.