But although performing solidly in the three races so far, Bottas or Felipe Massa are yet to finish on the podium.
"Sundays have not been a complete success for us," Finn Bottas told the Finnish broadcaster MTV3. "Certain things, like strategy, have been left to be desired.
"But we think really good results are still to happen, hopefully as soon as possible," he added.
The 24-year-old admitted that the industry-leading Mercedes engine had been an early boost to Williams' 2014 form.
"Especially in Melbourne we felt that the engine was a definite advantage," said Bottas.
"But the difference was smaller in Malaysia and Bahrain, as the others are developing all the time."
At the same time, the FW36 is consistently showing some of the highest overall top speeds at circuits.
Bottas said: "That also reflects the weaknesses of our car. Maybe we have a little less drag than the others, because we also have less downforce.
"Sometimes, what we gain on the straight, we lose in the corners," he added.
It means that, although a pre-season favourite, Williams is currently the lowest-ranked team with Mercedes power, behind the works team, Force India and McLaren.