The oil-filled damper (to give it the correct term - the shock absorber is actually the spring, and the damper dissipates the energy in the spring in a controlled (damped) manner to avoid oscillations that give poor handling and roadholding) will need an amount of energy to start moving that is more than energy required to start a damper tube moving.

In pan cars, they are usually light and so the energy that is imparted to the damper is quite low. If the design of the oil-filled damper is not well thought through, then that energy won't be enough for a smooth movement - it has to build up until there is enough to overcome the viscosity of the oil - and the car lurches into the corners. Additionally, there is a friction force between the o-rings and the piston rod that has to be overcome throughout the stroke.

A damper tube relies on the very low shear force in the (silicon-based) oil between the piston and cylinder, and is much easier to start moving, as well as keep moving. As this oil is not only the damping medium but also the sealing medium, it has very low static friction as well.

Having said all that, one might conclude that the damper tube is the preferred choice. It is, if the oil-filled damper is not the right design, and the friction in the o-ring seals is high due to poor design or poor build. Additionally, it is easier to build a good pair of damper tubes than it is to build a good oil-filled damper.

The Associated Micro-shocks are good items, they work well and give good performance. However, and it's a big however, they only work well if you understand how much damping is needed, and how to build them so they have minimal static friction from the o-ring seals. New drivers to 12th and GT10 will have more success with tube dampers than oil-filled dampers, but teaching someone to build a proper oil-filled damper is part of the fun of pan car racing!! HTH (but if not, come back with more questions!)