Actually the Subaru Legacy is more of an actual mid-sized sedan rather than
barely, as well as the Mazda6 if you take a glance at the dementions. Even though they're roughly 10 inches smaller in length and width, thus being a full class smaller then the others you compared.
As for the Jaguar X-Type, I have heard of it being unreliable but I guess how unreliable, I don't know and with hearing from many owners hear about how problematic it is, it is probably not worth getting as a good all around sedan.
As for the Hyundai Azera, it isn't too surprising that you don't know about it. It made its first appearance at the New York Auto Show, and had some good coverage but obviously not as much as any of the concepts or a more luxurious plus extensive sedan such as the Acura RL. But that doesn't make it a bad sedan, actually far from it. To sum it all up it is slotted to replace the XG350 by Fall 05. It is a full-sized sedan that it meant to compete with a baseline luxury sedans such as the Lexus ES330 and Acura TL at the price of a entry level sedan, sort of like the Grand Prix. However unlike the Grand Prix the Azera will receive many things standard such as the 5 speed automatic with triptonic shifting, dual climate control and the 3.8l 265hp V6 with CVVT, so it shouldn't be underpowered, as well as other features. From what is reported the Azera should start out at $21-23k and in the late $20s fully loaded.
Here is Hyundai's site on the Azera, as well as an
article that covers it and if you are too lazy or can't find the specs
here it is. So if you and your friend are still looking around for a sedan in Fall, give the Azera a try.