E46 m3 is a great all round car.
As you have mentioned there are only a couple of things to be aware off.

The floor is one, the vanos is not a massive issue anymore and they can be repaired or replaced for around the 500 mark, not the 3000 it used to be many years ago on the E36.

Don't set your heart on a low miler, buy on condition and history.

Great car.