I can understand the frustration. At BOS, there are always well-staffed counters for 1K/Polaris and *Gold, so I've never really even thought of using the self-serve kiosks outside the Premier check-in area.

The other month, I was completely overwhelmed at PHX when trying to navigate the post-NCAA finals crowd (was there for a wedding personally) when the Premier line was 50 people deep and the kiosk area was a free-for-all and I'd never used the machines before. I think there was roughly one agent working the kiosk area. Needless to say, I missed the bag cutoff by 5 min, they wouldn't make an exception, and it was a very long trip home (but was able to be rerouted through SFO/EWR to enjoy the 757 up front).