Will they hold my Polk RT55s? On Crutchfield it says they support up to 25lbs. each. I'm pretty sure the Polks weigh more then that. I don't want to order them and have them collapse on me. If anybody has used these stands before, does the speaker sit on the stand solidly without being able to be moved around easy? I have an SVS next to my left main and the SVS pushes the Polk around on the stand it's currently on. Had to velcro it to the stand. I like the look and price of the Sanus' so I'd really like to get them.