I'm sooo confused. I read the poll results that indicate over twice as many prefer MS over PS, then read all the posts and it seems the other way round. Have I missed something???
Okay, we use LAYOUT tabs for everything EXCEPT the model itself, and a very few annotation elements that we want to see in "EVERY" file no matter what.
Now whether we're working on the model in the Model Tab, or through a paperspace viewport, depends on what we're doing at the time. Usually we work in the Model Tab with multiple viewports while we're building the model, and rarely go to a layout tab until we're ready to begin annotation or make a model review plot. Now, once we've begun annotation, we'll spend a lot of time in Layout tabs, reaching in through a viewport or two to edit the model in some way.
It is my experiance that those who do a lot of "model" work through PS viewports are unaware that you can use the VPORTS command in a Model tab to create "tiled" viewports.
For us, EVERYTHING is plotted from a layout tab (or tabs), including charts, and schedules. No drawing is fully MS, but some are fully PS.