While the Italian supplier claims it is a minor tweak, others are concerned the change will favour only some teams.
The team that lobbied hardest for changes is Red Bull.
"I think there was more talk than action from our side," world champion Sebastian Vettel said on Thursday.
"For sure there's a lot of attention and people trying to make up stories, but I think you could see the whole grid struggling with the tyres.
"It's not a secret, it's not just us," he added.
Ferrari's Felipe Massa also confirmed that he "complained".
"I like this change," the Brazilian told Totalrace in Barcelona, "because before the hard tyre was not exactly hard."
Red Bull's Mark Webber is quoted by Auto Motor und Sport: "It benefits everybody if the working range is better and easier to get into."
What is also clear, however, is that some teams - especially Lotus and Force India - lobbied for the status quo.
"In general, when the tyres are softer, we got them to work better," Kimi Raikkonen told Finland's MTV3, "but if your car is good, it usually works on any tyre."
Force India's Adrian Sutil told Totalrace: "For sure some teams were pushing more than us for the new compound, because we were very comfortable with the old tyre.
"But it's a new challenge and let's see who can get used to it quickly."