I accidentally drove my car for a few months with the ALDA effectively removed, loose atop the IP. Long story short, my fuel economy picked up 5-10% after the ALDA was re-installed, and the smoking at low boost was nearly eliminated. When adjusted/shimmed properly, there is no power loss, and minimal (if any) smoke.

Note that if the car has been driven gently for many years by a previous owner, it may smoke noticeably at full throttle / high RPM, but the more you drive it hard, the smoke should gradually go away (at least until you drive the car sedately for a while, which will carbon it up again). As a general rule, it's a good idea to give the car at least one full throttle blast to the redline through the first 3 gears (speed limits permitting), at least once per tank of fuel.

BTW - if the engine is in top shape with proper fuel delivery, you 0-60 time in the wagon should be roughly 12 seconds, maybe less, if you're near sea level (assuming flat road, accurate speedo, stopwatch used, etc etc). The sedan is about 1 second quicker.