Try to setup the access points on the same controller to prevent too much inner controller roaming. For example.... if you have 2 4404-100 and you have a max 100 ap's, what you can do is either have all the ap's on WLC1 and use WLC2 as a backup. Another way is to separate the ap's to WLC by floor. Floor 1-3 on WLC1 and floor 4-6 on WLC2. The roaming should be fast anyways, but as long you try to keep the user on a certain WLC then you wouldn't have to worry about the roaming between WLC's. Hope this makes sense.