Single Comment

I have two observations.  First is that I think wide boards actually
increase the relative value of diagonal movers, not orthogonal ones. 
Consider a very long narrow board.  It will take a diagonal mover many
moves before it can hit a square on the opponent's half of the board,
whereas an orthogonal mover can do so on turn one.  On a wide board, the
diagonal mover has more squares from which it can attack squares in the
opponent's camp.

Secondly, I agree about unit density.  I am currently working on a large,
complex ultima-like game with powerful unorthodox pieces.  I found that
the game only works on a 10x10 board with three rows: one row of pawns,
one row of guards (with value intermediate between pawns and pieces but
without the pawn's ability to promote) and one row of pieces.  Unit
density is 0.60.  Immediate development is slower than in orthochess, but
because units are more mobile than orthodox pieces, the game heats up
pretty quickly.  All of the games I have playtested, and there have been a
lot, have ended in less than a hundred moves.  The game isn't quite ready
for posting to these pages but if anyone is interested in seeing what I'm
talking about and wants to email me, I can send them a 'beta' version. 
It's quite playable and interesting, I think.  But you'll only like it if
you like games that are more complex and somewhat wilder than orthochess.