I have owned the GAN 400 2 times to use with the LRS+. The first time was because I had it in the house when the LRS+ arrived. It was rather good and had more than enough power. I have a PeachTree GAN1 that was modded by Tweakaudio.com and it does not have enough power to drive the LRS+ (200 watts).
My issue with the GAN400 was a bit of hardness on top. I sold it for that reason. However, I bought it back again since I was not able to figure out what amp to use long term. I spent $1000 on the used GAN400.
The GAN400 seemed to drive the LRS+ within striking distance of the Magtech and the CODA #16. That is with punch and soundstage size. The Sanders and CODA sounded better overall. No hardness, just beautiful sound, especially with the Yggi+ Less Is More DAC.
For the price the GAN400 is good. I owned the Parasound A21+ before but not when I had the LRS+. I have a feeling that would be even better than the GAN400 but not the Sanders or #16.