Is that the free version or the paid version?
These type to things turn out to be a process of elimination.
Since you have disabled everything in the start up folder, then disable ObjectDock and see how long start up takes.
Then enable ObjectDock and reboot. If it is noticeable slow, then delete all the items from the dock. Start adding them back one by one and see which one might be causing the slow down.
I think if you contacted support they would probably suggest doing this. Hope you find what it is.