I haven't heard the Sphaeron, but I am very familiar with the Triolon Excalibur. It is, by a wide margin, the best speaker I've ever heard. I really can't imagine what the improvement might be, but I will say that the Triolon is the first really expensive speaker I've ever heard that didnt seem to be affected by the law of diminishing returns.
How could $325k be justiied? Pretty easily, IMO. If given the choice between the Triolons and a $300k car, for pure enjoyment I'd take the Triolons (and I am a car guy). I've known people with boats in that price range that they used a few times a year. People spend a lot of money on a lot of things, and I can't think of anything under half a million that would give me the long term enjoyment of even the Triolons. If the Sphaerons are even better...