I am seriously considering converting to hexes for the new edition. I never really liked the 1, 2, 1, 2 counting for diagonals in 3E, but I don't really like 1 for 1 diagonals either. I also just like hexes.
Certainly, hexes do reduce the number of people who can be adjacent to a target, but I think that is a good thing. Allowing eight people to flank equally well is nothing more than an oddity of square grids. Hexes get this closer to what it should be, since there is no longer a slight difference between types of flanking.
I don't see what is so hard with larger than medium size creatures in a hex grid...