I've owned two E46 ///M3's in the past (..PY w/ IR interior; IB with ///M cloth-leather), and the most recent E46 - an IB Comp. Package coupe lowered on TEIN coilovers - was my all-time favorite car. I ultimately traded my coupe for a 330i sedan because of a past relationship (..long story!!!!!!). I eventually traded the 330i for the new ///M3 sedan. Had I still owned my '05 Comp. Package when the E9X M3 arrived, I'm not sure that I would've been eager to trade up. I truly loved that car!
On the flipside, I really love my current ///M3 as well. They are different, yet familiar. I do still get excited when I see a lowered IB Comp. Package E46 though. Nostalgia probably!