Problem is with an E46 so many variables can affect how it feels and a lot of the time most have not been given the attention they need in terms of mechanical sympathy, which cost comes into it too. If the bushes are worn then the handling won't feel as planted as they should, even the convertible is well planted and agile on fresh unworn bushes. Then the engine if left completely stock only has a whiff of induction noise.
Also was the VANOS in good order? If not then the timing and power delivery won't be smooth at low RPM or urgent at high RPM.
You really want at least an Eventuri (was £550 when I got it, now much more expensive sadly) brings the induction noise close to CSL standard if it's on a 2005 or 2006 model as theys hare the same thinner CSL manifold so have more meat to the sound. The CF induction noise also resonates the cabin in different ways at varying RPMs from 3000 to red line so that in itself is an extra experience. Then when you blip the throttle on downshifts you get the intake and ITBs doing that bark/crack thing which just sounds excellent, it's loud enough that pedestrians walking on the pavement will get startled. You don't get that the same way with the stock airbox installed.
Also manual gearbox over SMG for obvious reasons.
There's loads more of course and they all add up to making or breaking the driving experience of the E46 specifically.