You'd be surprised...
Sean Tucker's Pitts' have all had RV rod gear on them - so do a number of Pitts that have been modified over the years by Steve Wolf and others, and a number of other planes use the tapered rod (although not from Vans) such as many of the Cessnas, Tailwinds, Lancairs, etc.
If they are set up correctly for what ever airplane they are on, they work fine. Steve Witman came up with them, that's why they are often called the Witman tapered rod gear.
Oh, and the rod gear dramatically improves the ground handling of the Pitts over the stock gear, which I can attest to.