I think the Bilstein shocks and the 6th gear are worthwhile additions for road trips.

The comfort level of the car is all relative. Compared to typical Japanes four door sedans, its a firm ride, mostly due to the damping. Smooth roads or roads with rounded bumps/dips are fine for long road trips, but if the roads have lots of compression lips (e.g. many urban freeways/highways), the car will beat the crap out of you. No two ways about it. I switched out the stock tires for something with a softer sidewall, and that helped a bit. I suspect that changing out to Swift Springs would help too.

Out on 60+ mph highways, the interior is louder than most Japanese four door sedans. As someone said, its not the exhaust. Its the tires/suspension/wind noise. Lack of sound deadening is the reason. I'm taking my Evo in next weekend to get Fatmat installed in the doors and on the front wheel wells.

The car is great for daily driving. The great handling and power make the car so easy to get around in traffic. The relatively high seating position makes it easy to see what's happening around you. Fine for traffic jams. Road noise is not a problem at DD speeds. Turbo lag is not an issue with the IX, and I personally like that the car is relatively gutless below 2700 rpm. Makes it easy to drive smoothly in traffic.

Lastly, wanted to mention that getting a flash can improve the driveablity of the car and greatly improve the fun-factor of the car. I went with a Vishnu flash on a stock motor, and got a nice increase in <3000 rpm torque. If you do go with a mail-in flash, I definitely recommend that you monitor knock sum after the flash with EvoScan. As much as everyone claims to have a conservative flash, its not always the case (my case), and you pay for the damage if the flash kills the motor.