LR4 still inadequate since doesn't have Levels Tool

I said that levels adjustments are a subset of curve adjustments. That's true.
I can get very close by adding 2 nodes very quickly.
To match a midtone level slider of 2: Try pts at 4,16 and 57,122.

Happy to post an example:
http://www.photoluminaire.co.uk/posted/gamma_curve.psd

Andrew