The first ML speaker I owned was the SLM - I was shocked at the incredible sound. I had this same experience going from the SLM to the EFX. I used both as mains for home theater and stereo. Each Martin Logan product is amazing. The EFX sounds like a huge speaker and all the fine details of sound is present. When playing stereo, I had to check my other speakers several times if I was running surround sound... because the sound is so subversive. It wraps around me and can not be pin pointed to a source. Placement is important but not hard to set up - distance apart and the angle towards the listener make a big difference. Not too far apart seems good for my room (8’). The bass is light with this size speaker, of course, but with a subwoofer and proper set up of the audio processor, this can be resolved. It takes a long time to break in. I don’t think mine ever did until I moved and was able to play loudly. I highly recommend.