I have not conducted the comparison you are seeking, but I do have some experience with the Audiosector Patek v2 chip amp, which I have used for at least some period in all three of my audio systems. I have definitely not encountered any of the negative characteristics that you mentioned with the Audiosector amp. That is to say that the amp has excellent dynamics, it is not at all thin sounding, and its treble is pretty refined and not at all grainy.
The Audiosector amp has significantly more power than is needed to drive my speakers to extremely loud levels (my speakers range in sensitivity from 93dB to 98dB). Based on the average SPLs that you mention, I would expect the Audiosector amp - at 40 to 50 solid state watts per channel - to have enough power to drive your 88dB efficient speakers. However, I wonder about the sort of impedance load that is represented by your speakers. I think you will get the most out of any chip amp if you present it with a higher impedance load and minimal dips below 4 ohms. Chip amps tend to run hot and experience stress if you ask them to drive low impedance loads at other than subdued decibel levels.
The Audiosector amp has significantly more power than is needed to drive my speakers to extremely loud levels (my speakers range in sensitivity from 93dB to 98dB). Based on the average SPLs that you mention, I would expect the Audiosector amp - at 40 to 50 solid state watts per channel - to have enough power to drive your 88dB efficient speakers. However, I wonder about the sort of impedance load that is represented by your speakers. I think you will get the most out of any chip amp if you present it with a higher impedance load and minimal dips below 4 ohms. Chip amps tend to run hot and experience stress if you ask them to drive low impedance loads at other than subdued decibel levels.