6 inch vs 8 inch auger.

[Giuga10]

I recently bought an 8 inch auger and it is hell drilling holes with. I've seen on numerous websites that the 6 inch is much easier for drilling. I was wondering if anyone had any pros and cons for either size and what you would get in this situation. Keep in mind that I fish for just about anything. Would I ever come across a fish that wont fit through a six inch hole?

Any help is greatly appreciated.

Thanks,
Giuga10