Ive been playing
40k for about a year now and I'm preparing for the
NOVA open and I love their missions, they give many more armies a competitive chance compared to ITC. Some of the differences are... No random malestroms, the ability to choose secondary mission objectives, choosing your primary goals (turn by turn scoring or end game scoring), and also very limited rule changes (mostly rule clarifications). I like these missions and I think they help give alternatives to ITC all the time. At least that's my two cents.
Here's the link to their main site.
http://www.novaopen.com/warhammer-40k/