Here’s my opinion on the whole thing.
Thre’s no point in bringing back the F duct. The only reason it was good last season is because only McLaren had their’s optimised. Introduce it next season and everyone would have a good system, and if everyone can use it anywhere there’s not strategic value to having it. I’m not entirely sure how you would limit its use, and it’d would be difficult to tell who’s using it. Plus it would bring back ugly shark fins.
KERS recharged after 2-3 laps might be a good idea, but it could be a lot less effective than DRS if drivers use all their KERS, fail to overtake and have to wait for 3 laps to overtake again.
Here’s the thing. It’s very difficult to tell if DRS is making races better because of the overwhelming effect Pirelli tyres have on the race. One could argue if we need DRS or F duct at all. DRS was introduced really “to improve the show” but Pirelli tyres have done just that. Would we still be rating China a 10 if there was no KERS or DRS, but just Pirelli tyres? I think it’s possible we might have.
It’s early days and I think we need to give DRS a chance over the season, but from my eyes DRS is a solution to a problem already solved.