The debate rages on about the role of the GPU, Open GL, and other current gen compu-speak processes. But right now, what we know is this; the more dense your file (notice I didn't say BIGGER), the more slowly it runs. Density come in a variety of flavors, but the 2 biggest culprits are Data and Model. The "I" and "M", if you will. While data richness is my life's goal and shouldn't be reduced, the Model can (and should) be. One of the the easiest way to control the Model is through the...wait for it...families. Before you think it, this is not a discussion of 2D vs 3D (in my opinion, there is no discussion, but more on that later), but a discussion on View Frugality. That is, showing what is important to you and not showing what's not. While a complex, fully realized 3D family can bulk up your KB, it doesn't have to muck up your view render time. Through a couple of responsible family creation maneuvers, you can have the leanest, meanest, Chuck Norris-est project on the block.
Visibility, Detail Levels, and Symbolic lines...Oh MY!
Long story short...
- ALL forms to be turned off in Plan/RCP (maybe Front/Back. Left/Right, if your elevations are giving you fits too)
- The most highly detailed bits (nuts, bolts, washers...j/k) should be set to Fine ONLY!
- Symbolic Line representation of the family.
What Revit can't see, Revit can't generate. Problem solved.
So stop all this worrying about file size, and focus on better creation. 2D vs 3D is another Red herring. The most highly detailed model and the most generic family of lines are separated by but a few hundred KB. Building Responsible Familes is everyone's responsibility.