There appears to be much confusion over this topic as well as a definition of what each does that seems to be somewhat blurred and cloudy. Allow me to offer one perspective:
Reload Latest: simply updates your local file from changes made on the central file. This is a one way process and is usually accomplished pretty quickly (<5 seconds)
Save to Central: Updates the central file with all the changes you have made since your last 'Save to Central' operation. There are 4 operations that take place when you use this command: 1) saves a local copy of your file, 2) saves your changes to the central file, 3)Reloads all the changes that have taken place since your last Reload Latest or Save to Central operation, 4) saves your local file with all the updated changes.
Considering there are 4 things that happen here, it can take a while (30 second or longer) to complete all these steps (depending on your file size of course). While one person is accessing the central file, no one else working on the same project is allowed to access the central file. Revit does queue people up and access the file once it is available, but if you are trying to save to central while someone else is, you get a warning box that pops up saying it is waiting for its turn, but it does give you the option to cancel the operation if you wish.
One method that is considered a 'best practice' is to use the 'Reload Latest' and 'Save to Central' commands only when you wish to do just that. Don't Save to Central if you are simply wanting to download changes that another user has made. It will take longer and may un-necessarily update the central file, sending everyone else in an endless cycle of saving to central.
What is the solution? Get used to using the 'Reload Latest' command if you are simply looking to see the changes that someone else has made. By default the Reload Latest can be found at 'Collaborate -> Synchronize -> Reload Latest'. You can also add it to your Quick access toolbar by right clicking on it and saying 'Add to Quick Access Toolbar'. You will notice a symbol with a blue down arrow appears on the quick access toolbar.
You can reorganize the toolbar and have it be placed next to the Save to Central Button if you wish. Right click on the toolbar and say 'Customize Quick Access Toolbar.' You now have a dialogue box, click on the symbol you wish to move and then use the arrow buttons on the left side to move the order up and down to get it to what you prefer.
Start using 'Reload Latest' and save yourself time and hassle!
