I've tried out quite a few of the different hacks. I used to use Cake, it was good quality and very reliable. Now I use Sanity 5. Pretty similar to Cake. High quality, reasonable file sizes, totally reliable.
I've tried a few of the really high bitrate I-frame ones, and they just havent been reliable (Flowmotion, Unified, etc). I use Sandisk 45mbps cards, but for some reason, I almost always got card speed errors with Panasonic glass (my kit lens or 7-14mm), but only sometimes with vintage glass or the 25mm f0.95 I have rented. I don't know if this has to do with the sharpness of the glass, or the fact that the electronic connection takes up some of the processor speed in the camera. For me, the reliability issues arent worth the increase in quality, especially since pretty much everything I do just ends up on the internet anyway.
Pretty much just have to read around on personal-view, try out a few different patches and figure out which one works for you. Some of the ones that people rave about on there have been totally unreliable for me, but some that people have had problems with have worked fine for me.