well ferrari had a 1-2 so looks to have been a bad move for RB to keep the renault engine with it's associated reliability problems
or perhaps I should say that despite the fact that ferrari had a 1-2 , RB made an excellent decision to stick with renault engines ; the ferrari engines appear to be thirsty and suffer from overheating problems , and RB only failed to win due to a faulty spark plug [ hands up anyone who believes the alonso bullshit that he could have won anyway ]
depends which end of the telescope you look through
personally I think that if mercedes engines were unavailable renault engines were the best choice , but that is purely subjective ; renault never had any great success until they bought a british F1 team , but they were always in the top drawer on the engine side