This past Friday I had my first DL IRROPS in months, possibly over a year. Flying MSP-SEA-RNO, the OO-operated E175 from SEA to RNO that evening was cancelled due to thick wildfire smoke in RNO reducing visibilities below minimums. Before the gate agent even finished his announcement when it was cancelled, I was on the DL App and successfully rebooked on the next mornings SEA-RNO departure. I didn't have to wait in any lines or make any phone calls. It was flawless as far as IRROPS goes. Sure, I had to spend an unexpected night in Seattle, but that was beyond DL/OOs control and given how bad the smoke has been lately, I'm okay with a minor inconvenience to get home safely.