Over the last few weeks I have picked up a couple 6" dobs, the first is a 6" Celestron StarHopper, it is a good scope with a spherical mirror, my only issues are that it is very wiggly when I touch it, I have done my very best to make the mount glide in its movements but it seems that it just doesn't want to move and then just gives and goes past where I want it, or it doesn't give and goes right back to where it was, I have soaped up the base and put felt on the sides last night, but it was very cold last night so maybe it needs to warm up, the other issue is the secondary mirror mount, it is only held on with one screw shared with the focus assembly, the cardboard in that area is kinda beat up now, I got it collimated real good, but if I have to start twisting on the secondary collimation screws it can mess everything up and I have to start all over again, I am considering either drilling two more holes in the secondary mount and threading them and adding the 2 screws but it might tilt the secondary up, if it does that then I may mount the mount on the other side in fresh cardboard and use the 3 screws to mount it there, and then twist the secondary around 180 degrees and collimate it that way unless there is a reason not to do that.
These are the felt pads I installed.