I rebuild bikes for a local charity. One of the regular challenges is removing and remounting tires. I have a Koolstop that I use for pulling the last few inches onto the rim but can not be used remove tires. It is also only 6 inches long providing limited leverage.
The Unior Tire Setter has better leverage and handles both mounting and dismounting. The only problem I've had is holding the tire and adjusting the jaws one handed. It usually takes a few tries to get the right opening. On my next use I plan to put the wheel on a wheel holder to free up both hands during the initial adjustment process.