What version of NX are you running?
Starting with NX 8.5, if you're creating a new Drawing from scratch, your views will either be 'Exact' or 'Smart Lightweight', and you'll be able to switch between them with no real hassles. Just select the view(s) of interest and with your cursor over a view's boundary, press MB3 and select 'Settings' and you will see option to set the 'Representation' for the view(s). If you select, 'Smart-Lightweight' you'll also have the choice of three different resolutions.
If you're working with Drawings created in a version prior to NX 8.5, you'll be more limited in what you can do, generally only having access to 'Exact (Pre-NX 8.5)' views. Now there is an option to use a 'Lightweight' view but these cannot be dimensioned, sectioned, change the Hidden Line display, etc. In those cases, if you really feel that you need to use a 'Lightweight' view and yet you wish to retain most of the functionality that you would have using an 'Exact' view, then YES, you would need to replace the legacy views with new ones.
And speaking of 'Lightweight' views, even starting with NX 8.5 and the introduction of 'Smart Lightweight' views, you should really ONLY go that route if you're creating Drawings of very large and complex Assemblies. There should be almost NO rational reason why you would want to use 'Smart Lightweight' views when detailing single piece parts, no matter how complex those models might be, and even when you feel it helps performance enough to warrant their use in situations like this, you may still wish to limit them to pictorial and illustrative views, not necessarily where you will be doing a lot of dimensioning and adding appended annotation.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.