Is useful at all as a competitive Pokemon? It seems like the moveset of the other pokemon will be diverse enough that it would have some moves effective on itself. But are 's stats just not worth it?

Use Smeargle insted. The moveset possibilities are endless, and its stats are better.

Yes definitely use Smeargle. Ditto is too predictable. I mean as soon as you transform, you've either taken a hit or lost a turn to some setup/switch out.

@ Mektar; Smeargle's stats are better than Ditto's, but as soon as Ditto transforms he's going to copy the stats of the opponent, which is inevitably better than the pathetic stats of smeargle's.

Ditto has only two uses:
- Transforming into Shedinja or Shuckle in double battles.

Disagreed: It is good in competetive battling because i have one trained in Pearl and it's actually decent. Especially when most people don't paln on facing an opponent thats the same as one of their pokemon when creatign teams. It's also a good way to experience using different pokemon. I was stuck on creating a team and decided to go all random on wifi and got a good taster of 3/6 out of the pokemon i have chosen so you can't really say it only has 2 uses.

Also~ Does it matter if Ditto's stats are bad, all you really need to worry about is the Speed and HP because the HP could damper the first hit thet gets it before transforming and the speed determines whether you transform first. All stats change after transforming except the HP so after EV training HP (assuming you do) it's actually mid-decent. It's also a good test of skill, two Pokemon exactly the same battling, you'll probably have less max HP.

But yeah, definatly worth a try and it's not as useless as people say.