The Copy/Monitor tools tend to be a Love/Hate relationship in that very order. In fact we have recently been using the batch copy functionality because we sincerely love it due to its flexibility. But that love is fading quickly due to some unexpected repercussions.
A common scenario to employ this tool on, has been when a Lighting consultant/designer is working in a separate model (for design purposes only, not for documentation) and our Electrical Engineers need to circuit these lighting fixtures and document them in their power and equipment drawings. These fixtures need to be hosted in the electrical model for proper circuiting. Copying and pasting fixtures one by one from the linked lighting model is highly inefficient. Opening the source model to copy and paste into the documentation model also doesn’t work due to hosting issues (most of these families are face-based and cannot be pasted) and also due to the fact that Paste >> Aligned to Same Place uses the Internal Coordinates to determine location and this is not always consistent between models. On a side note, best practice dictates that you link other discipline models via Auto – Origin to Origin to avoid these problems.
We have received several reports and anecdotes of performance degradation when copy/monitored fixture counts are high, so we have been disabling monitoring soon after the copying is complete and resume with manual coordination from that point on.
Unfortunately when you stop monitoring by using the dedicated tool, MEP categories become pretty much useless as they can no longer be modified!
EDIT: Refer to this post. If you try re-hosting, you have to use the workplane positioning option, which is not desirable. I am not sure why Revit even asks you to do this because copy/monitored elements do not have a host in their properties.
There seems to be no work-around, short of deleting all fixtures and starting over, which is really bad. Lesson learned: Do not stop monitoring with the dedicated tool! If you want to stop monitoring, remove the link. Once you do this, none of the MEP categories will behave as shown above and you can freely move them around and re-monitor at will. These categories then pretty much start behaving as Levels, Grids, Columns, Walls and Floors, which we can stop monitoring at any point without experiencing the same repercussions.
At least we now have a plausible workflow for future projects and the love for the batch-copy tool has been (cautiously) restored.
The nice thing is that you can specify type mapping and only batch-copy one fixture type at a time. Just make sure that if you want to use this as a pure copy tool with no monitoring, to then remove the link soon after. You can re-link it back in, but this is currently the only safe way to stop monitoring without putting future revisions to the position of these fixtures in jeopardy. Autodesk has recorded this behavior but there is no estimate when this will be addressed.