they don't take off til they hook up - enough root mass reaching to the res. they're a slower start, but they grow faster through veg, and flower the same rate as hp type or soil. all assuming photo. auto is a dice roll.
most folk forget that hempy is actually intended to be a micro grow style. it surprises folk since it produces as a macro.
my 5L buckets easily match or produce more than my 5gal/20L hp/soil did. my 2L buckets can almost touch what the 5L does with coaxing. i grow for canopy, so 2L or 5L it doesn't matter. the number of plants change, not the yield.
i only have 4 x 4 for flower space, so it would make no difference in yield even going back to hp/soil. inputs and grow time would change. mostly in veg.
hempy is similar to coco. feed often and hands off. any issues that arise come quick. any fixes happen just as fast. it shares that with dwc and rdwc.
hempy, coco, or any other passive self water hydro style will tie you closer to the grow. soil and even hp type have a bit of an advantage that way.
typically myself and most of the folk i know local try to keep indoor growing to winter. oddly, winter is the prime growing season. it's easier to control environment, and pests are naturally kept to a minimum.
plus you get to enjoy the summer sun without the pressure. our summers are short and hot. it's best to enjoy them and not worry about growing. growing here is for when it's cold and depressing outside. makes it sunny and happy inside.