I'm having the same decision to make man! Doing heavy music production/light video editing in my situation, and am also curious if this 10% increase is reasonably priced. I found this benchmark test, may help you out a little: http://www.cpubenchmark.net/high_end_cpus.html
The difference in base clockspeed and Turbo Boost clockspeed is 300MHz for the CPUs. So at the base clockspeed the i7-3740QM is clocked 12.5% higher than the i7-3630QM. At max Turbo Boost clockspeed the i7-3740QM is clocked almost 9% higher. The max Turbo Boost clockspeed assumes only one of the 4 cores are being used. If all 4 cores are being used, then the max speed is lower. That is also assuming the CPU itself is within a certain thermal limit. If the CPU temp is too high, then Turbo Boost is limited or disabled. If all 4 cores are being used the max Turbo Boost clockspeed may only be 3.3GHz for the i7-3740QM and 3.0GHz for the i7-3630QM exact clock speed is unknown and the only possible source of info is Intel technical white papers for their CPUs which has a lot of technical data that is likely very difficult for a layman to understand, much less process.
It all boils down to how much is your time worth. Let's just say a the performance difference is 10% to keep it simple. I've done some video batch processing of my own from time to time and in once batch I had around 20 videos I was encoding. Based on the settings I used to do the video conversion, it tool a total of 50 hours to compete the entire batch. A 10% increase in performance would have cut that down to 45 hours.