Kimi Raikkonen says the 'halo' protection system that was tested for the first time on Thursday made "surprisingly little difference" to his visibility from the cockpit.
The Finn became the first F1 driver to try the new device when he went for an installation lap with it fitted to his Ferrari in the morning at the Barcelona circuit.
Raikkonen said that while the visibility was slightly reduced towards the front, the different was not significant.
"A little bit limited in the front, but I don't think it's the final version," said Raikkonen. "Surprisingly little difference."
Although the Ferrari driver has been the only man to run with the device attached to his car, several of his colleagues had strong opinions on the new concept.
"I saw a picture of it," said world champion Lewis Hamilton before putting the palm of his hand to his face. "That's my opinion."
When asked to put his gesture into words, he said: "No, I won't give you a soundbite."
Force India driver Nico Hulkenberg labelled the device as "horrible" and said he felt it was not needed, as it was sterilising Formula 1.
"For me it looks horrible," he said. "I don't like it. It's just one of those personal things. I wouldn't like to see it.
"I think it sterilises the sport. There needs to be an element of danger that makes it sexy and attractive and that's also what Formula 1 needs. Back in the day it was a lot more.
"In the last 20 years we've done a hell of a lot for safety and if you see the accidents that we've been having and you just walk away without a scratch.
"Obviously there's a balance but I feel pretty safe and for me we wouldn't have to do it."
Red Bull's Daniil Kvyat echoed Hulkenberg's thoughts, saying that Formula 1 needs to maintain an element of danger.
"There are many controversial opinions and so on," said Kvyat. "Formula 1 is an open-cockpit racing, it is more dangerous like this but Formula 1 is dangerous.
"Open-cockpit racing is open-cockpit racing, it wouldn't be anymore open-cockpit racing.
"I am racing also because it's dangerous and I am able to accept it - so that's my opinion."
Felipe Massa admitted the decide did not look good, but insisted he is in favour of introducing closed cockpits.
"It is not so nice. For sure the safety is the most important thing and I totally agree with the halo or closed cockpit," Massa said.
"I agree to do this change, but it doesn't look very nice to be honest. So we will see how it is going to be."