Brandon,
Like many other choices, it largely depends on your budget and your preferences. I learned on Matlab, but at the time I was a student and had access to Matlab for free. Then I went to work for a series of large, well-funded organizations that had the money to pay the annual licensing fees to purchase Matlab. When I started my own company I evaluated Matlab and the parallel computing libraries, and found that it didn't really meet my needs. It just didn't work well enough to justify spending $1000 or more of my own money on licensing fees when Octave is such a comparable product. I do think Matlab is a bit more developed in some ways, but not enough to justify the cost difference to me. Your decision may be different depending on your circumstances and the licensing arrangement available to you.
- Mike