There are many arguments for and against dropping development of a car in-season.
But we should remember there are no guarantees as to time/speed cycles.
Teams may even have to scrap the design before it races as McLaren have done before.
Personally I think Brawn should terminate development if the W01 is not looking racey by June. Saying that Rosberg is only 4 points of the lead of the WDC(commendable really) with what is the 4th best car out there.
Also in terms of upgrades, China will have no surprises. Everyone at Mercedes have said wait till Barcelona, then judge us. Rosberg is expecting quite alot with Schumi and Haug being more reserved. How they will overcome the nigh on 1second gap to Red Bull is the main problem because even a brilliant update is usually only worth 0.4-5 seconds a lap. How will they overcome the added 0.5 seconds plus anything that Red Bull bring?
Its a very very tall order but the saving grace for Mercedes is that their cars look more reliable, and so can take advantage of any Ferrari and Red Bull problems(Ferrari already on their 3rd engine in Malaysia plus well documented issues with Red Bull).
The competitors may turn out to be McLaren! I think if you add the F-duct to the W01 it is a match for it. The W01 suffers more drag than the MP4-25 and so would benefit hugley from the device. The proof is in what it can do on the track with all the updates added. Expect China to be more of the same, but as an avid Mercedes fan I pray Barcelona brings a car that is worthy to challenge Red Bull etc throughout.
PS FIA have banned the use of leveling devices on cars. How will this affect Red Bull?
Excuse my War and Peace, i had 10 mins to kill!

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