Thanks Keith...last time I got into this debate..."over there"...I was the only one stupid enough to admit to using multiple xrefs and got chewed up purty good (or bad, as the case may be)...
Here we have a large number of components which must be designed, and then have shop prints made. All these components are then xrefd into two or more assemblies (skid, flare etc...) which are then combined into a site layout. If I threw all these assemblies and sub-assemblies and individual parts into one file, it would be from 40 to 90 meg! So....now how do I "break out" each of these parts to create shop dwgs? Can you immagine the nightmare of layers and dimstyles.....?!? Xrefs rule, gents!