I love "dpi". Total marketing tool, nothing else. As long as your mouse has 400dpi you're good. After that it's just a higher sensitivity, and y'know, you can adjust that anyhow..
It's genius though. They can re-sell the same mouse over and over, only adding "5k DPI!!!11+1+1" every time and a new package.
Not quite. Games have a limited "max" sensitivity. So does your puter's OS sensitivity controls. Higher DPI will get your mouse even faster. My games and OS are both maxed all the time and I have a huge difference between setting it to 400 dpi or 4th setting which is 2400 dpi. So much so that I can do 360 by only moving my mouse about a 1/16th of an inch.
More your 1600DPI mouse 1" and in game, your aim shifts 45 degrees.
More your 800DPI mouse 1" and in game, your aim shifts turns 15 degrees.
High DPI is good for very quick gross movements like running around and quick close range combat in FPS. You can turn 360degrees with a very small mouse movement. High DPI wins with gross movement because it takes time to move a mouse. However, low DPI is good for fine movements like snipering. A smaller dpi mouse movement makes a 30degree change. Easier to make the 2-3degree adjustment for that headshot.