The arm is built steady and has a ton of possible holes to fit your TV.  I had to go through many options before finding a combination that my Sony Bravia needed.  I bought a pair of 5/16" screws that were a little longer (3") than the lag screws included since I have 1/2" sheetrock over plaster and furring strips.  I also put some felt on the bracket being fastened to the wall so not to damage the wall.  The arm moves in every direction other than up & down.  Well worth the price paid.