It certainly has a steep learning curve. I'd say steeper than NLP and SmartConvert. But it's also more powerful - you can mask certain areas and dodge & burn, you can select a film stock profile and then adjust the amount of cross-talk, super-detailed settings for shadow / highlight density as well as WB adjustments, etc..
I still like SmartConvert for its simple workflow, esp. with Black & White film. But I'm seriously considering switching to NegPy for color.