Ursaring is probably one of the best wallbreakers in the PU tier, due to his high attack stat. With Quick Feet and the boost from Timid, it can certainly outspeed quite a number of decent Pokémon, and attacking decently. However, Ursaring won't be hitting as hard, due to Timid lowering its attack, so it might be an issue there. If Ursaring don't get the kill as fast as possible, it will get worn down by Toxic Orb (you know, to activate Quick Feet), plus Entry Hazards. Heavy Priority Users can cut its longevity short or potentially just K.O. it. Even so, physically defensive Pokémon, like Tangela can tank its damage and just heal off with Synthesis or something. Another problem would be quicker Choice Scarf Pokémon, and even though they can't just switch into Ursaring's attacks, they can still outspeed Ursaring in the right conditions, and take him out with STAB. Overall, Ursaring isn't a great competitive battler, and I wouldn't recommend putting him in compeitive battling but hey, who doesn't want to show off your awesome green Ursaring? Its obviously worth keeping but not for battling.