For me, it's the dynamic range of the audio. I know it's closer to the "theater experience", but my girlfriend and I both HATE the way the volume will fluctuate from way too quiet to WAY too loud. I was watching Jason and the Argonauts the other day, and I kid you not... I don't think there was a period of longer than one minute where I didn't have my finger on the volume control. Sometimes I had to pump it up to 30 to hear the dialogue, and other times I had to turn it down to 12 to protect my eardrums. (As a side question, if anyone knows a way to control the volume range better (like some kind of compression or gating device, maybe?) please let me know.) I also hate double-dipping, but I'd rather buy a disc twice than never get an SE at all.