I think their main issue was the wide tank which robbed useful space of the radiators.the car simply was too fat in the rollhoop area .
As you cannot change the tub it did not make sense to stretch the wheelbase and so basically they were stuck with what they had and crucially could not add drag by cranking on some more wing ..maybe a function of the fat belly of the car .
it´s not for nothing Mercedes is not really developping much in terms of front wing over the last years...they have struggled to balance their front downforce with rear df..
Hopefully this is sorted and the extra length is used to carry KERS within the bellhousing and the packaging of the tank has led to a trimmed down waist...
I´m positive .I´m convinced W03 will excell on tracks where a stable aeroplatform is king and at least occasionally be a frontrunner.I remember all too well how Button raved about BGP001....and sure Schumi will deliver in similar fashion if things fall into place..