The nighttime IBOC began in the US

As we all know many AM -stations in the US switched into the IBOC overnight operation on "Black Friday" September 14, 2007. Since then many local AM listeners in the US have found AM band to be noisier and DXers over there have noticed the digital "hiss" sound especially around the powerfull stations all around the AM band and all around the Nation. The IBOC signal covers 15 kHz to the both sides of the station's nominal frequency. I do hope that the situation here in Scandinavia does not change as dramatically as a DXer in Kingsport, TN wrote:
"I gave a listen to AM early this morning for the first time since IBOC came on. It was about 1am local time.... . .boy was I disappointed... . .*sniff* . .I felt a sinking feeling in my stomach. I COULD NOT BELIEVE all the hiss. I listened for a few min's and went to bed. I hope..HOPE that maybe my neighbor had something on like a light w/dimmer switch. I'm glad I have BUNCHES of cassette tapes of AM radio the way it used to sound so I can "re-live the good-ol days".
The next weeks will tell us what are the US IBOC nighttime effects on NA-DXing here in the Scandinavia. Hopefully not too bad...