Quote Originally Posted by Lampada View Post
Опять же, в таком случае я бы сказала щель оказалась достаточно вместительной для чего-то.
Я вижу в Яндексе примеры с просторной щелью, но я всё равно против такого употребления.
I don't see any reason to say all those words if you can just say просторный. That word refers to the space just partially, it refers mostly to the feeling you have.

Haven't you ever heard or used this expression: чувствовать простор, чувствовать себя просторно?

That's why it would be rediculous to use it like that: - Камню будет просторно там - that's a stone! It doesn't feel anything
But it would be just fine to say like this: - Вове будет там просторно - Vova is a person, he can feel

Given the above, I don't see why if someone feels простор in the gap, you can't say that the gap is просторный. But, yes, that gap can't be просторный for a senseless stone, for the stone it would be just вместительная or широкая as you said above