I own a Lazer 6'' and it is great for all panfish; plus you can pull medium- large bass through if you need. It cuts great, but we don't often get really thick ice, either. One winter I was cutting 20'' plus, which is a real workout if you tend to be mobile. A 5'' will cut easier, but if you fish for big crappie, or even bull gills you might wish you had a little breathing room. You also have to consider your holes will ice up from the outside in, also reducing your margin for error. You can drag a fairly large fish through a hole that is slightly undersized, if (here's the rub) it is well hooked. It comes down to what works best for you. If you are catching perch and small to medium gills; say, up to 7'', a 5'' hole would probably suffice. If there are any number of big gills, or crappie you will be happier with the 6, IMO.