I have been using OV3 (great results, but painfully slow. You can catch up on your reading and chores while waiting for each update). I tried Raw Therapee, and may still use it for this and that, but it is pretty unstable, crashes often and regularly just bogs down. So, since Adobe gets no more of my money after they screwed me twice, and my Mac once, I bit the bullet and bought Aperture. Pretty happy with it, works well, not blisteringly fast but OK. Results have been pretty good, and getting better as I learn its features. But...to do perspective and/or distortion CX, you need an external editor or a plug-in. Another $25 for a decent plug-in. For one of the most basic things you (or at least me) need when processing photos. Disappointed. [Hey, I wonder if I can use Hugin as an external? Must get wife off of computer and try it.] P.