As someone who has used Chatter since 2011, it is a half baked product at best. My daily digests are mostly junk, it has no way to filter out, Uploading images looks like you went back to '99. Try uploading multiple images to one comment. Try replying to comments to create a thread... Want to view that image someone just added, no mouse over to zoom, you must click and leave the entire page to view. The feed if expanded takes up massive real estate on the screen to the point the rest of the page is unusable. I could go on, while their Lightning is a better take on it, it will take YEARS to move the bigger companies over to the LEX as they all have custom pages and solutions developed using the old styles, plus LEX is not fully baked yet, still some features missing.