Font smoothing for pdf files in OSX Yosemite Safari vs Skim

I produce a lot of pdf files using LaTeX and thus, I also read a lot of such files. After the update to OS X 10.10 the fonts are not smooth anymore. However, Safari seems to handle it much better than Skim (see screenshot for comparison). The option "Use LCD font smoothing when available" is enabled; without it, the texts are almost unreadable. Anyone has any clue how to make the font looking better? : (left quick preview [spacebar], right Skim): Hardware: I use non-retina MacBook Pro 2011 + Fujitsu 27" LCD attached with dual-head DVI.