As with most "best of" threads, the variables of ancillary components, room, musical tastes, etc. need be noted. With that it mind, my bias is towards tube amplification. I have heard the Eidelons driven by solid state in an audio shop with less than stellar results. Neither the Spectral/MIT, Rowland or Audio Research fared as well as some Eidelon systems I have heard. May well have been the store setting.
Lamms, Convergent Audio JL-1, and Atma-spheres have all brought beautiful music to these speakers. Atma-spheres may have the best bottom end with a touch less lower mid-range refinement; compared to the CATs. I have heard the Eidelons with and without preamps in line and have found myself leaning towards the open, detailed, and extended presentation of the Atma-spheres with preamp(much needed for love of analog). Close in second are the glorious CATs. I wish I could comment on other solid state, but have unfortunately not been exposed to personal play. It's hard to hear even a small percentage of what's out there, especially in a small market, so.....good luck. The speakers are just great, and revealing. Mating can be daunting, but oh so satisfying.