I found emacs terminal emulator (M-x term) to be very convenient. However, it is essential for me to time certain portions of my code accurately (in order to compare speed of different algorithms fairly).
To make sure that my speed measurements are unaffected, I have tried comparing the speed of the code using regular Ubuntu terminal (whatever shows up when I type "Terminal") and emacs terminal emulator and they seemed to be pretty close. However, when I started outputting things on the screen in large amounts, the emacs terminal emulator seemed MUCH slower.
I'm an emacs newbie, so I was wondering if somebody could confirm if my observation is correct: Speed of the actual computations is unaffected by using emacs terminal emulator, while the printout to screen is slowed down. Perhaps, if you know of something else that could be slow on the emacs terminal emulator, advice would be much appreciated.