I am playing the contemporary piece Lichtbogen (1985-86) by Kaija Saariaho this week. It is a 9-piece ensemble, and includes strings, harp, piano, electronics and lots of percussion instruments. The tricky thing about this music, and many other similar pieces, is the use of counter-rhythms, such as fives against sevens, in both hands, and very difficult counting throughout. After one rehearsal, it became clear that much of it is an effect and does not need to be exact. You still have to watch for the downbeats and stay in the flow.
Only in a few places does it have to fit perfectly with another player, and luckily those are not the worst places. I found it much easier after I wrote out a few passages that had the lines going from one staff to the other. By putting it all on one staff, my eyes were able to see the patterns much more fluidly. I also found the font to be very small and hard to read, so I enlarged some of the notes. I will keep the changes that I made, in case anyone needs to see what I did.