One of the biggest problems we see in installations of stair treads and landing tiles are the heights are not lining up.  Meaning there is a little bit of a step up at the transition.  Most stair treads a tapered to the back of the step, therefore the the tiles are a little taller.   To correct this all you have to do is sand the back of the landing tiles were the treads and tiles line up.  All you need to do is sand about 2-3 inches back with a block sander, if you have a larger volume of stair treads in install, you can use a vibrating sander.  The back of the landing tiles sand easily for the perfect fit.  This can also be done to the stair treads if you are trying to have a smoother transition to a floor without any coverings.  We sell a complete line of Rubber , Vinyl, and Landing Tiles on our website.