My feeling is that you should only do I6 CT if you are 100% committed to it. You are right, while both may be tough residencies, there is a "light at the end of the tunnel" in Ortho. You have more freedom to shape your practice, and do private practice. There is also less uncertainty about the Orthi in general when compared to CT. While Ortho is competitive, right now I think I6 Cardiac is the most competitive specialty. With that said Id recommend doing a subinternship outside of your home institution to really get an unbiased feel for it. I have heard the U of Michigan provided a really great med student experience. Schedule one your 1st month of M4, if you like it do another or 2. At the same time set up ortho electives in the same time slots. If you do not like CT enough just cancel the CT ones and go with Ortho. Hope this helps.