I have been debating the height. I have a worktable that is 30" and at 5'7" myself I find that to be an ideal height for seated or standing work, although for seated work I can always use a taller chair to meet the height of the table. For standing work when I am standing straight up and lay my hands flat on a 30" tall surface it is a natural position.

I can buy existing rolling carts that are 31" tall and I may make the table a bit taller in order to use manufactured rolling carts and save time building them. It's actually also cheaper once you figure the wood and casters to buy the existing ones. I may split the difference and make it 33". Thanks for the feedback.