Matt, the car's powertrain is impeccable. It's smooth and quick, plenty of power, and surprisingly refined and remarkably well-balanced for a transverse V. The mileage is of no concern on a car this well made. You're unlikely to discover any mechanical issues of any significance before 100K miles plus - maybe even not then. No one here is at that point yet.
The suspension problems are common, but by no means universal. Many folks on here report it because they
came here to report it; others are just car enthusiasts and they developed the problem over time. The way some folks describe it, the suspension sounds like you're driving along with blown shocks and all the rubber bushings are gone - rattles and clunks and all. That's a little hard to explain. Others (some with a lot more miles on their cars than ours) say the suspension is A-OK and has been all along. Some are in the middle and report only minor issues and not even "problematic" - I'm in that category, with my own Azera. We own two 07s; the suspension on mine got a little clunky, and I pulled the wheels off and tightened up a bolt on the strut tower a couple of months ago, and it has been quiet ever since. My wife's, with twice the mileage, still has whisper-quiet suspension, no problems at all. If you drive it over broken pavement and it feels / sounds good to you, then that's your answer. The car is FINE.
Others report the wallowing / porpoising issue. That's another one that seems to be a matter of taste and expectations, not a matter of flaws. The car is somewhat 'floaty' on the highway - but lots of cars are. Again, it's not consistent. The way some people describe it their cars are like riding on jello, vibrating and flopping all over the place and barely able to stay in a lane. Others say it's fine, even great, no problems, it does what it's designed to do on the highway quite well. Usually the same folks who have trouble with clunking also have trouble with highway cruising - so there is some type of consistency there, in the car and/or in the individual driving it, or both. If you take it for a spin for a few miles of highway and it feels good to you, then that's that - no problem. The car is fine.
Last is leaning. This again isn't clear. Again, usually the same folks report this issue with their cars. When taking fast corners they report sloppy handling. I do not get this in any way so I can't really distinguish whether it's
leaning or
body roll that is being experienced. Maybe I don't take my corners fast enough. (IMG:
style_emoticons/default/grin.gif) Again - if you drive it the way you like to drive it, and it feels fine in corners, then that's all there is to it.
There is a TSB regarding the clunking suspension, some of the early shocks began to leak prematurely and were (or will be) replaced under warranty. For those having catastrophic issues with their suspension, the revised gas shocks do not appear to have helped much, if at all. To date, no one here is aware of any aftermarket options for the Azera's suspension, and it's not for a lack of trying - folks have called all over the place, searched every parts site, called reputable aftermarket shock manufacturers to inquire as to their plans. The general position is, the car is too young. They likely will not produce aftermarket options in the U.S. until '06s and maybe '07s are beyond the 5-year warranty. There are Korean coilover shocks that can be retrofitted to the Azera (I forget the brand) but they are fairly expensive.
Good luck and enjoy the car (if you buy it)!