The 787 is 8 across in coach. The 350 is 9 across. The 777 is 9 across, or 10 if you want to squeeze them in. Most 777's are now sold 10 across. They are all similar range.

Airbus is now offering the 350 with 10 across. 16.3 inch seat width. Yikes. I have been in a few 10 across 777's (16.7 inch). It sucks.

They all do about the same thing, with about the same range. The 787 has 13% less seat capacity. And they break a lot. And worse, they attract scabs.