Car/engine shake when releasing the clutch pedal

[Edd]

For the most part, the tranny is about the same quality as many cars a class or two (or three) above. Just because it's a cheap car doesn't mean it has a shorter lifespan. Fortunately a manual transmission is fairly simple. It's the automatics that aren't as good in the Yaris as more expensive cars (shift intelligence, number of speeds, shift speed and smoothness).
I do agree that the Yaris has a smaller engine and less low-end torque than many other cars, so it's a bit harder to get moving. It IS lighter, however than cars with bigger engines, so it's not THAT much harder.