I just discovered I left a damn NSLog instruction in the QLFits3 implementation. It was clearly slowing down every preview the generator was producing (in addition of filling up your logs).
You should quickly reinstall it. Here is the one-liner for that:
curl -fsSLk https://raw.github.com/onekiloparsec/QLFits/master/Scripts/install.sh | sh
iObserve 1.4.2 has just been pushed for review. This update fixes two small issues with manual coordinates for new objects, as well as the webservice URL for individual exoplanets. This should prevent the planet mass and other important parameters to disappear upon update. Oh, and the buttons (and other small visual tweaks) in Mavericks have been restored in their previous shine… Interesting to realise that many users are still on Mavericks! I guess you all wait to be sure that iraf, MIDAS, ds9 work as usual on Yosemite…