I have both the 50/1.4 and the 50/1.7. I never got warm with the IQ of both of them. The style is too... flat, like cheap holliday pics in the 80s.
The 1.4 perform mediocre at 1.4 and both are nothing above that against the other two lenses, I have in this range (FE 55/1.8 and leitz wetzlar summicron 50/2), in any regard.
I have all 3 including the 85mm planar.
1.4 on the 50mm is soft, but from 1.8 or so on, it's quite nice.. I find the bokeh/colors to be very pleasant... at 2.8 its incredibly sharp and a very versatile portrait/landscape lens.
1.7 has a bit of a nervous bokeh, but it's a sharper lens from the get go than the 1.4.. planar beat's it in sharpness around 2.5 onward.
IMHO the planar's have smoother bokeh than the sonnar, but the sonnar's are sharper... I find the 55mm to be a great lens and quite sharp, but I was hoping for a better minimum focus distance
planar is .45m while the sonnar is .5
with my contax 28mm 2.8, I can practically get right up to the object.
85mm 1.4 kills all 3 in bokeh