Not quite true. The analog version is inherently parallel, the digital version is not (cf the MATLAB simulation discussed in the paper). The parallelism of the analog system increases exponentially with it's size, the digital system only linearly. So an analog computer built in the way they indicate might be able to create a useful and powerful practical system to test quantum algorithms on long before quantum computing becomes a reality, whereas the digital model cannot be more powerful than the computer it is running on and will struggle to model even moderately complicated quantum systems.