I love the machines. LH were the first ones, years ago, for domestic flights out of FRA. Now there are banks of them everywhere, including some that weigh your luggage and print the tags. You put them on yourself and put the luggage on the belt. (LH was even talking about sending a bar code to your cell phone for check-in and getting rid of paper completely somewhere around 2000. Not sure where that stands)
The U.S. was a late adopter. On the other hand, now you can check in online for most U.S. airlines, which I love even more. I travel mostly with cabin luggage only, so this is brilliant. The downside is that if there is a problem (say, a one-way first class ticket bought the same day that flags you as a potential security risk) you have to get in line - and the lines seem longer now that they cut down on staff. But by and large, I really like the machines/online check in.
Some of the machines now even read your passport, so you can check in on international flights. Memory is blurred, but I believe it was Continental that allowed that? Not sure
Happy flying