I've just upgraded SW2014 and i've noticed in assemblies when I make parts transparent the edges of the part go very thin and wiry. I dont remember this being the case in SW2013 and before and from watching some videos online other users edges maintain the same thickness as when not transparent. I've read transparency in 2014 has been changed so might be to do with that? I've tired out all the various options in the performance and image quality settings with no improvements. Attached an image for reference hopefully you can see what i'm talking about.
Something to note, i've just upgraded my PC including an upgrade of my GFX card from an ATI friepro 5800 to a W5000 which is one potential difference worth considering. I dont have SW2013 installed on this machine...but I guess that's an option to compare. Another option is to swap out the gfx card and see if it makes any difference.