I've just completed creating a 49x83 inch butcher block countertop for my new island. I'm oiling it up, and I'm so excited about it. I'll post pictures at some point, but this is awesome.
I got "carpenters grade" butcher block because I liked the look of it with the knots and bits in it, but it wasn't square by a mile. After biscuit-joining it, there was an (to me) unacceptable gap between the two pieces. I routed out a 3/4" trough and glued in a new strip above and below the biscuits. It's incredibly strong, and even though I have a 21" over-hang, it's secure. I actually jumped up and down on it, and it's solid. No posts, just cantilever iron brackets. I can fit six stools around it.
I am slowly redoing the whole kitchen. I went from virtually no counterspace to a huge island, and more. My kitchen is shaping up to be awesome. Working now on the pantry that will be on either side of the fridge. 30 inches on either side, 20 inches deep. That's a lot of pantry.
I'd post pictures now, but I took them on my iPhone, and I don't know how to remove the personal data that would allow you fartheads to dox me.