Most SCT owners do not dare or want to collimate their telescope.
Collimation often is a drastic way of improving performance of a telescope.
SCT's are extremely sensitive to collimation. Collimation can be achieved and destroyed with the slightest movement of the collimation screw. Most users stop when the shadow of the secondary mirror is centered in the disk of starlight. This step is necessary, but is only the start of the collimation process. Due to a lack of information most owners do not know how to properly collimate their telescope.