The jumpy feeling is because the computer can only "drive" a manual as well as a driver can, with the throttle, clutch in/out, and moving the gearbox to a new position. Hydraulic automatics that use brake bands and torque converters are a lot smoother... but there is a definite torque/HP cost to that. It has gotten a lot better with better automatic transmission design, but an AMT will always get better fuel economy and power since the power isn't having to be transmitted and received through a container of auto transmission fluid.