It's pretty nice looking to me, a bit fussy for others. Plusses include better breathing than leather (waayyy better than vinyl), it warms up faster in cold weather, it can help keep you from sliding around if you have roadster style seats like the ones pictured. Make sure you get a heavy (16oz) upholstery grade fabric or you'll be sorry. Thinner/cheaper stuff gets baggy and stretches out. If you're not doing it yourself, make sure the upholsterer understands how you want it to look (matching pattern, major accent color going horizontal or vertical, etc. Like how the vertical stitching in the example goes along the red accent lines in the pattern and uses matching thread).
Original 356's had corduroy insets, and later the 911's had a houndstooth they called pepita. Even later they had a pattern called pasha. Pasha is not for those effected by vertigo and would look particularly bad on a 356.