No doubt correct RIAA EQ is better than no EQ at all, but truth be told the main thing the EQ in your MM phono stage does is change the constant velocity response of your magnetic cartridge to constant amplitude. Ceramic cartridges are most commonly fed into a high level input with no EQ with satisfactory results. I seem to remember reading that Peter of Soundsmith doesn't EQ his strain gauge cartridges which are also constant amplitude, claiming the difference is not worth the extra processing which EQ would require.
In this Pioneer soundbox the stylus must drive two diaphragms which I believe will give constant amplitude. The Pioneer thing ideally should sound similar to a piezo-electric or strain gauge cartridge.
If you read the copy on the first page, it claims the bass is surprisingly good. And it covers 30-15,000 hz (no deviation specified, however
Kind of hard to believe the bass is good, since the record will be played back with no RIAA eq.