It largely depends on the user, company workflow, and understanding of Revit.
If you are just focusing on drawing pipe and fittings (I'm a Plumber) and nothing else then I would say it's the same.
In general detailing in Revit vs Cad is a little slower. That is the initial modeling of pipe and fittings.
Modifying pipe and fittings already drawn for coordination etc. is faster in Revit. Shop drawings (annotation and dims and sheet creation) is a little faster in Revit. Overall it balances itself out.
The loss in productivity is mainly due to Revit not able to spool and do point layout out of the box like we can in Cad. Less properties exposed on ITM's in Revit than Cad so customization is limited. Any company using Fabrication for any length of time has invested in workflows using scripting and Autolisp to automate tasks. That automation is mostly lost in Revit with the exception of Dynamo or has to be re-created in Dynamo so Revit can be automated.
There isn't much of a reason to 3D model something if you aren't using that data to Install / coordinate / fabricate a product faster.
The more you want out of CADMEP parts in Revit the worse it gets.
For Revit it's all about View manipulation and control. If users can't orient themselves in Revit views to perform detailing tasks then they are sunk. Once that is learned the time is relatively the same.
Revit opens 10 times slower than Cad.
Revit is version specific, different versions have different capabilities especially when talking about CADMEP parts.
For CADMEP parts I would not use and Revit version older than 2018.3. Yes the .3 matters.
How are you working with Arch and Eng and what version Revit are they using?
Revit work sharing / central model thing or C4R or 360 Design Collab complicates how you will collaborate with multiple users. For example all users collaborating in the same model should have identical Revit versions (including service packs) installed or weird things may happen. Speedy access to central model or internet access. Are collaborating users remote or local?
Working with Navis on the Revit side is a little slower. Larger file sizes and / or longer nwc extraction times.
