I tend to think of a "toothpick" staff as one that is either very thin, or made of a very lightweight wood. Either way, the result is a very light staff that is easy to use with lightning speed.
The problem is that these are very unrealistic weapons. They dont have the strength needed to stand up to any real contact use, and would simply break quickly if ever actually employed as a weapon.
they tend to be favored by people in tournaments, as a way of winning thru flash and speed, while trying to hide the fact that their form and technique is not solid.
Personally, I use a Chinese waxwood staff that is quite thick and heavy for its kind, both for my staff work, and my spear work. My spears have heavy, thick, steel heads; no lightweight, sheetmetal, modern wushu spearheads for me.
Use of a hefty weapon develops your strength naturally to be useful for the purpose of using the weapon correctly. It also forces you to use proper technique and doesn't let you cheat. If you try to cheat with a heavy weapon, that usually means you are swinging it with your arms, and not using your body properly to power the strike. With a heavy weapon, your arms will get tired very quickly and you won't be successful. With a light weapon, you can cheat and only use your arms, and you don't even realize it because it doesn't tire you out. Using a heavy weapon will show you the problems in your technique pretty quickly.
Overall, if you are using a hefty weapon, you will be better off for it. You might still use a lighter weapon for tournaments and demonstrations, but at least you have developed good technique by practicing with a realistic weapon, and you can dazzle the judges that way, instead of with empty flash and techniqueless speed.
When I compete, I use my heavy weaponry, including my Chinese Broadsword. I cannot move as fast as the guys who use the lightweight Modern Wushu junk, because my stuff weighs about 4 or 5 times as much as theirs. But the judges definitely take notice of my weaponry, and I usually place pretty well with it because they respect the tools I am using.
By the way, I custom make all of my weapons, including my swords, because I cannot find stuff on the market that I am happy with. I mount heavy spearheads on heavy waxwood staffs, and I make custom hilts for my swords, after I find a better quality, heavier blade. Everything is solid, which is not the case with 99% of the junk you can find on the market.