IMO, it’s the air suspension that makes an allroad an allroad. Arnott Industries makes some very good quality replacement bags for these, and sells compressors for about $380. I wouldn’t even consider going with spring/shock on mine.
But I agree about the turbos. Just enough extra room/ventilation that they don’t run quite as hot as the S4 turbos do, despite having the exact same engine code (for 01-02 anyway).
Other stuff to look for. If it’s an automatic, and hasn’t had a torque converter replaced, it will need one at some point around 100k miles. Every one, no exceptions. Exhaust gas temp senders are common. Obviously, the typical belt/pump maintenance, control arms/ball joints (lowers are allroad-specific), inner axle joints get loose and vibrate, secondary water pumps leak. But a lot of what I’m mentioning is typical of any Audi. Just keep up on things as they fail, and you’re ahead of the game.
I would never want another car. I truly love this thing the way it’s set up right now. No, it’s not crazy fast, but it holds its own just fine. I find myself occasionally having to drive other cars home for various reasons, long term issues, intermittent concerns, etc, and unless it’s something really wicked (modded TT Porsche, various exotics), I find that I’d rather be in the allroad.