I think it all depends. The LCD-2f easily outpaces the EL-8 Open (2016) that i had. IMHO, the EL-8 was a definite upgrade from the 400i. Though, $250 for the 400i is a good deal. $500 for the LCD-2f is fantastic. I'd pay $700-800 for them, but very happy that i got them on Black Friday deal. It does help to amp them properly as well.
The only thing that really hold back the LCD-2 and all LCD series headphones is the weight, and with a average clamping force they can fall off if you move your head forward or backwards.
I actually like my EL8 open (2014) better than my LCD-2f, mostly due to the weight issue but also because the mids of my EL8 are more natural to me and they have a touch better sub-bass as well, seems like my EL8 is a freak in this.