I have both but have not shot them side by side or compared them directly.
In general I would say (some of this you already know since you own the Canon 50mm f1.4) is that I would agree that the f1.4 has what most people will call a "modern" look. Fairly sharp and contrasty at most settings with good color and good contrast. It is very forgiving in this regard. I would call its bokeh fairly neutral I think.
The 50mm f1.2 is quite another animal in some respects at least. I love "character" lenses and this is a character lens. I has a tendency to flare due to its large front element so a hood is needed. Worse (for some) it is very low contrast when shot wide open though as a result it also produces what can be nice pastel colors at these settings too. As you stop down it changes character and becomes sharper with more contrast though my own still tends to low contrast (though this may be because the coating on mine is not in good condition). Mine begins to be pretty sharp at f2.8 or so. And it is quite flattering as a portrait lens.
As to bokeh I think I prefer the f1.2 but I have not really shot it for bokeh for some reason and my impression is that it is rather smooth as you might expect but not quite so ultra smooth and gooey as you might have thought. Never the less it is good. Here is a nice link with some good samples (though not all taken with this lens).
You will also get an idea from this article which by chance I found and re-read only a few days ago. https://themachineplanet.wordpress.c...unting-around/
The following image by me was taken on an earlier Sony NEX camera stopped down a trice to perhaps f2.8 or maybe even f3.5. Because of this and the positioning of the background the bokeh is not really shown to good advantage but it does at least show the low contrast this lens tends to produce. I do not mind that incidentally as it is something that can be fixed in post and in any event I prefer low contrast on digital sensors. And of course with most digital cameras you can in any event elect for a camera to produce a "vivid" image through its own in camera processing if this is your desire.
In summary I tend to think of the f1.4 as a general purpose lens that I can pop on the camera and use for most purposes but the f1.2 is more a special purpose lens to be used when a different look is wanted. (It also looks damned cool on the front of a digital camera).
Those Eyes - Color
by Life in Shadows
, on Flickr
I have not used the 35mm lenses so will leave it to others to answer.