I looked at the reviews of the Ocean Wonders and there are a lot of complaints about the design scratching the glass.
I went ahead and ordered the Buiding an Obsession L Series Blackout and received them a moment ago.
Well, upon unboxing, I found some instructions that read:
"Place the inner bracket at the position inside the tank you wish to place the rack. Carefully place the outer bracket to match up the inner bracket. DO NOT slide the bracket on the glass to move the rack, doing so you may catch a foreign particle between the tray and glass and scratch your tank."
So... it looks like I won't be able to slide the rack up and down at all if I want to or it will scratch the glass? Is this the same will all the magnetic racks and it is just a matter of time? I am considering returning these or selling them.