i'am not sure where this is going.
but for info i no a freind who have had 620 avons with 150 vmax
on the back cracked the hull not his doing bulid quality, took for ever to get replaced, also boats chinerided with any small amount of trim , and wos slow on top speed took about 3 weeks
to sort it out lifted engine moved weight in boat around changed prop allwent very well after that.
its.unfair to slag a boat off if it's not set up right.
perhaps your freind should get some one to sort it out
i.am sure if he phoned mike ring up he would sort it
if you can't