Center sharpness and resolution never was a Tessars weak point quiet the contrary in the center a coated Tessar should be the planars equal.
For portraits and subjects were I want to draw the viewers attention to the center of the frame I prefer the tessar. When I need corner to corner sharpness (some architecture and some landscape work) I use the planer (rarely). The Planar Rolleis are usually a little heavier than the Tessar Rolleis so for hikes and street the Tessar is the better choice. If I had to choose between the Tessar and the Planar I'd choose the Tessar because it's lighter and because the picture it makes draw the viewer in whereas the planar creates a uniform neutral image.

Dominik