Review Warnings - Me Too!
I am officially jumping on the bandwagon.
REVIEW WARNINGS!!! This is a huge factor in file size and performance, especially if you're using worksets. If you're noticing performance degradations opening and closing the central file across the network, this may be the culprit.
Have you ever gotten one of those alerts in Revit that tell you that you just screwed up but give you the opportunity to just hit "OK" and keep going? Of course, in that case, that's probably what you did, right? After all, it's the easiest way out, and usually there's no obvious problem with the model after that. Just one of those Revit quirks,right?
WRONG, Grasshoppah. Go to the Tools pull-down menu. If the "Review Warnings" item near the bottom is not greyed out, then you've got problems. Possibly big problems. (In this case, having something greyed out on a menu is actually a good thing - it means that there are no unresolved issues in the model that Revit can see).
If Review Warnings is not greyed out, select it and note how many unresolved errors there are. I've seen as many as 400 or more in a single file. Each one of them is a potentially serious problem in your model somewhere that needs to be resolved. At the very least, it's increasing your file size. At worst, it's increasing the chance that your model is becoming corrupt.
Resolving the issues sometimes takes a little detective work, but it's usually not that difficult. First, select a warning and click "Show". Revit will attempt to take you to a view that shows the offending elements and highlight them for you. Sometimes this doesn't give you any clues, though. Next step, expand the warning and select one of the elements involved that will be listed. Again, click "Show". If this doesn't produce any answers, then you can use the "Select by ID" tool. First, note the element IDs of the elements involved in the warning. Then go to Tools and use the "Select by ID" tool to go to the object and actually select it. This usually pays off with some sort of clue. Worst case, delete the sucker and see what happens.
Whatever you wind up doing to resolve the error - be it deleting offending elements (for example, duplicate coincident walls) or moving something that may be out of position and causing problems with something else, as soon as the error condition has been dealt with, the warning will be removed from the Review Warnings dialog.
Once you get used to this, you'll find that a) you're hitting "OK" a lot less often, and dealing with the error right up front and b) you're reviewing warnings daily, if not several times a day. The effort will pay off in spades in file size, performance and stability.
But don't take my word for it - see what others are saying:
Steve Stafford in Revit OpEd
JB Zallan in Fear and Loathing in a CAD vs. BIM World
Aaron Maller in Malleristic Revitation