The Eureka 147 System produced results that were far superior to any of the IBOC systems with respect to audio quality, signal reliability and non-interference to existing analog services.
FM IBOC systems would produce unacceptable interference to their "host" FM station, as well as to nearby stations that operate on adjacent frequencies.
AM and FM IBOC systems would produce substantially-reduced service coverage, compared to that of their analog "host" stations.
The performance of FM IBOC systems degrades considerably, even to the point of failure, in the presence of multipath. The AM IBOC system cannot provide CD-Quality audio and produces impairments that expert listeners judge as "annoying".