Moi has qualities that speeds up workflow, I dig creating 2d as well as 3dstuff in it.
For me, It's like working with an electric drill instead of a screwdriver.

Although it's a bit of pain having to do dimension in another app, there's options:

As mentioned, Rhino is the simplest, just open native 3dm files and add dimensions.

Alibre Express (surprisingly reads 3dm files and can be used for dimensioning, creating 2d projections of views and exporting .dwg and .dxf formats.)

There are several free 2d packages that can be also used for dimensions:
-Solid Edge 2d drafting (Very heavy, has interesting persistent constrain features)
-Free2design
-Vecad61 (Very autocad-like)

Marc