I find 4x4 to be common and too small. I also find 6x6 a bit too big to see if the deer are close. So I'd go with 5x5 with the understanding you'll have some waste.
Every place can vary but we have a hexagon on 4 foot sides. And an 8x8 square in anotehr place. Both have deer come by easily close enough for a bow shot and the hexagon we unfortunately have deer bed up under the stand now and again. They don't stay that long cause the dog can't handle it and will eventually whine or whimper some and they'll get up and walk off.
I think a small blind thats brand new woudl be worse than a huge blind thats been there...
