Probably only the smaller firms. Unfortunately, and even though it shouldn't be so, you will be at a disadvantage in the job market if you don't do articles at one of the Big 4. Many job listings list Big 4 articles as a requirement, especially bigger companies. It should be that a CA is a CA, but it's not true in practice. Some CA's are seen as being more prestigious, like first time passes for everything and Big 4.