I like the Soloist very much, and imo it is an excellent match to the Audeze line. Burson has been demonstrating their products using Audezes so I suppose they also like the combination very much.
Never heard the SL version but I have read here in head-fi somewhere the SLs don't sound as good as the big ones.
Only complaint is that the volume knob is stepped and makes switching noises when changing steps, but I knew this would happen before the purchase and also know that the best attenuators are built like that, so I endure this for the greater cause (better sound quality). Other than that, all is perfect imo.
Edited by Matias - 9/30/15 at 12:55pm