But ... the mirrored baseplate compass (Brunton 15TDCL, Brunton Eclipse 8099, Silva Ranger, Suunto MC-2) and I suppose the Cammenga lensatic compass can do BOTH map work and sighting bearings.

Mirrored baseplate compasses are VERY accurate sighting compasses - much more accurate than a simple baseplate compass. I'd venture to say that because of its magnified dial that the Brunton Eclipse 8099 is a bit more accurate than most other sighting compasses. The Cammenga lensatic compass is marked in 5 degree increments and the Ranger-type compasses are marked in 2 degree increments, while the Brunton Eclipse 8099 is marked in 1 degree increments, and with the 8099's dial magnification it is pretty easy to read to the nearest half a degree. The 5 degree increment on the lensatic compass really limits its accuracy unless you start working in the mils scale (ugh!).

The 8099's dial magnification is also better for those of us older folks who have problems reading the tiny numbers on some compasses.

Here is a good comparison of the Ranger-type compass versus the Cammenga lensatic, though I think the Ranger-type compass does better than the aritcle suggests. http://www.cammenga.com/uploaded_images/1147706028-TonyWilks_CAMMENGA_LENSATIC_UK.pdf

Mirrored compasses such as the Brunton 8099 & 15TDCL, Silva Ranger, and Suunto MC-2 and the Cammenga lensatic compass are as good as or better than a simple baseplate compass when working with maps because the mirror/sighting door actually extends the straight edge length of the compass when fully extended. Also, most of the mirrored baseplate compasses have 7.5 minute (1:24,000) topo UTM scales right on the baseplate. The 8099 also has 7.5 minute distance scales in feet and miles.