Bendpak, Atlas, and Direct lift use an adjustable lock ladder, which is captive to the cross bars which the ramps ride on. This has an advantage for a few reasons:
1) Since its captive, if somehow something twists the post, the lock is much less likely to disengage and the car falls.
2) The lock ladder hangs from the top of the post with a threaded nut. This nut can be turned which raises or lowers the height of the ladder. This allows you to adjust each ladder independently of the others to have the ramps sit perfectly level when the locks are engaged.
The titans ladder rail appears to be welded on, so it is not adjustable. If your floor is not level in any direction, your lift will be twisted when sitting on the locks. Seeing back to item 1, this could cause a lock to not have enough engagement surface and fail. It also may not be level front to back, which can mean the car will roll off if not chocked correctly.
Also, not having a secondary locking system is less safe should a cable fail. On the Titan, if the cable fails and you have the locking mechanism disengaged (lets say you are lowering the lift), then the lift will just drop to the floor or as close to it as it can get. With a BP, Atlas, or Direct Lift the secondary lock will engage the lock ladder and it will stop at the next lowest lock.