I've narrowed my choice down to one of these as both have front L/R pre-out and apparently much of the same remaining features except for Dirac (let me know if I'm missing anything). This setup is used mainly for watching youtube and TV so not a typical HT setup (no center speaker as we have no suitable location for that, need to use a simulated center via front L/R, and rear speakers are in the ceiling at 13ft height so anything but a great surround sound setup). Wondering if Dirac in the 3.4 is worth another $500 over the 2.4?