Does the Aprilia Tuono 660 have 'dead spot' in the mid range?

Now, one of the most talked about things in the Aprilia Tuono 660 community, both from owners and potential buyers, is the bike’s power delivery in the mid range RPMs. Some riders say there's a lack of power or responsiveness between 4,000 and 6,000RPM, a so called "dead spot" or "flat spot" in the power band. This feature has started debate on whether it is a major problem for normal riding, or merely a minor feature of the engine design. Opinions are split regarding if this affects the overall riding experience, and if it’s easily overcome by technique or modifications, or even if it compares to other bikes in its class. So let's dive into a few different views on how this performance aspect of the Tuono 660 fits in.