Plinius SA103, Spectral DMA260mk1 or Symphonic Line RG7 mk4

Hi,

how would you rate your experience with the following amplifiers?

Plinius sa103 - Spectral dma 260mk1 - Symphonic Line rg7 mk4.
Was there an opportunity to compare?
Which of the three would you with Audio Research Reference 1 and B&W801S3?

Thanks for the support.