Neither!

Z4 M Coupe all day long.

Just as focussed drive as the CSL, equally as fast, and no loss of creature comforts. Trades a proper gearbox for the carbon airbox.

The 1M is a poster car and not as fast as any of them. It has one of the slowest Nurburgring lap times of any modern M car.
I love the styling.
However it takes all the bits of the E92 M3 and leaves the best bit (the engine) behind.
The N54 turbo'ed cars never sounded that good either. My M135i (N55) with Performance exhaust sounded much better than a 1M.

What driver aids did the 1M exactly lack????
AFAIK it had all of them apart from having to change gear yourself.

And for the record the Z4 M Coupe is just as rare as a 1M with regard to worldwide production numbers.

However to answer the actual question, I would pick the 1M as its a much better looking car than the E46 even with the CSL upgrades, in my opinion.