Hello Nick,
first - NX is a shortcut for nonsense clicks. I am working every day with NX (4 years) and compared to Catia V5 (14 years with V4/V5) the workflow needs more meters of mouse movements. Surface design isn`t intuitive - everything seems to be possible, but hunderets of switches leads to try and error. Filleting in NX super- very stable. Sketcher sometimes gives surprising results while making constrains - other companies uses the same libraries from d-cubed (surpise owened by Siemens) The surface quality is good. Sheetmetal works fine. The assemebly concept works, but seems to be developed between the first and the second world war - maybe with respect to compatibiliy. It depends on that what you want to do and what are you missing at the moment. The only software I hate more is SAP.

Have a nice day
Karsten