Brandan,
If you are so worried about the centre channel, definitely go for the 150. It has wider dispersion and lower frequency response. Both of these will contribute to understandability.
I have the VP150 in a 4,000 cubic foot room. I usually sit 8 feet away from it straight on. But I can (and frequently do) sit as much as 60 degrees off the horizontal axis and 10 feet away to watch movies and I understand the dialogue without any problems. I am very happy with it.
The word "bright" is used to describe harsh highs. Axioms are far from harsh. As others have said, they are accurate.
It's not unusual for recording engineers to turn out bright CDs so that they sound better on crappy boom boxes like my wife's Sony. If you have a particular recording that is like this, use the treble control on your receiver to tame it.
I've noticed one other thing with my M80s (which I know that you are not interested in but I am sure it's the same story with other Axiom fronts). I can stand anywhere in my largish room and I still have great center imaging (ie. the center image does not move to the left or to the right). Also, if I go into another room, the tone of the speakers does not change. I attribute both of these observations to excellent sound dispersion characteristics. This is important because it brings a sense of ambience to stereo recordings.
