I had an opportunity to use the BX SSL E on a mix last week. I really like the vibe of this SSL channel compared to others on the market. It has a warm midrange. Here is the song I mixed, an Indie Rock tune with a female vocal, you can listen for free here:
https://choon.co/tracks/0ck8bbt2jop/the-void/
I used the BX SSL E on all instruments, with the exception of a couple of guitar takes where I followed the BX SSL with a UAD Trident A Range eq plug (love that EQ on guitars). The BX SSL sounded great on guitars too, I just wanted to introduce another flavor to help with the sonic spread. But all Vocals, Drums, Bass and Synth used just the BX SSL E. I randomized the channels, all in analog mode.
I already owned SSL channels from UAD, Waves and Softube, so I wasn't sure I needed another one, but I am glad I bought the BX. It has a dimensionality and warmth that has a pleasing cumulative affect.