Warning! Spoilers ahead for Dragon Ball Super chapter 78!
Planet Cereal's eponymous orbs in Dragon Ball Super only allow one wish per summoning, but they are proving to be much more powerful than Earth's own magical spheres popularized in Dragon Ball Z.
The Cerealian dragon balls are especially more effective than the ones on Earth prior to when the Namekian Dende altered them to grant three wishes. Like Earth's original dragon balls, the ones on planet Cereal can only grant one wish at a time, but those seeking to summon the eternal dragon Toronbo only have to gather two balls as opposed to the seven on Earth to seek an audience with Shenron. Even though Earth's Shenron can now grant three wishes, the amount of time that users must wait until they can summon him again is much longer than those on Cereal. Earth's balls have always turned to stone once all of the wishes have been made, making it impossible for anyone to summon Shenron again until they return to normal one year later. But as revealed in chapter 78, Toronbo's dragon balls either don't turn to stone at all or do for a much shorter period because the Heeter Force successfully summons him to make Gas the most powerful warrior in the universe not long after Toronbo granted Granolah the Cerealian's own wish.
Chapter 78 also provided another crucial aspect about Toronbo. He can grant the same wish more than once as made apparent when Granolah asked Toronbo to make him the most powerful warrior in the universe. That's how the Heeter Force got the idea to do the same thing for Gas. Shenron either can't or refuses to grant the same wish more than once even if they were made at different times. This is why Goku's friends are unable to bring him back in Dragon Ball Z when they ask Shenron to revive everyone killed by Cell since they had already wished to bring Goku back after his brother Radditz killed him.
Toronbo also appears capable of granting any request - but at a price. When Granolah originally wished to become the most powerful warrior in the universe, Toronbo originally denied his request since he could only make him as strong as he was latently capable. But he eventually concedes, revealing that he could grant Granolah's wish if the Cerealian were willing to sacrifice many years of his life to accommodate the amount of damage his body would sustain after receiving so much power. Shenron hasn't been nearly as lenient as his Cerealian counterpart. The eternal dragon famously denied Krillin's wish to change Androids 17 and 18 into normal humans because they possessed more power than himself, forcing the Earthling to alter his original wish to remove the explosive devices implanted in them.
Although much has yet to be learned about the dragon balls on planet Cereal, what Dragon Ball Super has divulged thus far has proven them to be much more powerful than the ones that summon Shenron on Earth. Users might be limited to one wish per session, but they can quickly summon Toronbo back - possibly immediately, a chore that is already expedited by the fact that only two need to be gathered as opposed to the seven on Earth. Additionally, once Toronbo has been summoned, the Cerealian eternal dragon has demonstrated that he is able to grant impossible wishes so long as certain criteria are met, usually at the detriment of the one who will be the recipient of the wish. Shenron either can't do this or he is unwilling to make any accommodations. It fits with his personality as Shenron has shown throughout Dragon Ball Z and Super that he is impatient, so it would make sense that he would be lazy as well.