I also thought long and hard about spending this much money on a pair of headphones. However, I have had some great Sennheiser headphones previously, and wanted wireless, so I took the plunge.
First thing you notice is how comfy they are. I can wear them for hours without any difficulty at all. The sound quality is excellent for wireless headphones (they will never quite match the quality of high-end wired ones though). They sound just as good listening to music (I mostly like hard rock and metal), watching movies or plugging them into my amp and playing electric guitar without disturbing the missus.
I have never reached the extent of the transmitter range, or the battery life, despite lengthy use, and some extensive wandering about in the garden, loft etc.
The charging is ingenious - there are two electrodes embedded in the headband, which charge the headphone automatically when they are replaced on the cradle. A system of LEDs tells you when they are charging, full, in use etc.
The bottom line is I'm seriously considering buying another pair, so I can have a base unit downstairs with the TV, and another upstairs with the computer and guitar. They are that good.