Suppose a buyer believes that the value of the item is v. Then this buyer has a simple dominant strategy: stay in the arena as long as the displayed price is below v; exit the arena whenever the displayed price equals v. This means that the Japanese auction is a truthful mechanism: it is always best to act according to your true value, regardless of the others' values.
When all buyers play their dominant strategies, the outcome is: A Vickrey auction is a sealed-bid auction, where all buyers submit their bids in advance, the highest bidder wins and pays the second-highest bid.
Moreover, the Vickrey auction is apparently much faster, since it does not require bidders to wait until the clock increases to the final price.
However, in practice, jump bidding is often observed: buyers increase the displayed price much more than the minimal allowed increment.
This may be seen as either an advantage or a disadvantage of the Japanese auction format.