I've been through so many bowls that slide across the tray, but these stay put even when my 14-month-old really yanks at them. The suction base is strong enough to survive his tantrums, and cleanup is way easier now that he's not flinging food everywhere.
Bought these for my 14-month-old who loves to fling her dishes off the tray. The suction base actually holds, and cleanup went from a full floor scrub to a quick wipe. Five bowls means I'm not washing one every single meal.