There were stays at boutique hotels featuring rooftop pools, private soirees at members-only, jacket-and-tie clubs and fundraisers at the Four Seasons, the St. Regis and the Mandarin Oriental.

In the world of Jeb Bush, the campaign for the 2016 Republican presidential nomination has at times been a whirl of private planes and high-end affairs, according to the federal filings of Bush’s campaign and his super PAC, Right to Rise, which can raise unlimited funds for Bush as long as it does not coordinate directly with him.

It is not unusual for US presidential candidates to fly private or even sometimes stay in luxury hotels. But some disgruntled donors say they are unhappy with Bush’s large outlays, which also include big spending on staff and tens of millions of dollars in ad buys.

Eleven of 16 major donors contacted by Reuters questioned whether it was money well spent, especially given how the one-time front-runner has stumbled badly in the polls and is now facing questions about whether he should withdraw from the race.

In contrast to Bush, Sen. Ted Cruz, who is running second in national polls of Republican voters, favors cheaper accommodation options like Holiday Inn and often flies on budget carriers, campaign finance filings through the third quarter show.

Several members of the Bush camp vigorously rejected the donor critiques. Bush spokeswoman Kristy Campbell said, “We are running a national campaign that is competing everywhere and we have made investments that have allowed us to do what serious campaigns must do to be competitive in the primary and general elections.”

Ad-tracking firm SMG Delta says Bush’s campaign and Right to Rise have spent $82 million on ads, significantly more than the three leading candidates in the Republican race: Donald Trump ($5 million), Cruz ($11 million) and Sen. Marco Rubio ($49 million). The tracking firm’s data is more up to date than what has been reported so far in the federal filings.

“There is no return on investment on the Bush ad buys, zero,” said one high-dollar donor who asked not to be named, pointing to how the ads have done little, at least so far, to lift Bush in the polls or dent his opponents.

On Sunday, donors will learn just how much Bush has spent from his $100 million-plus warchest. That’s when Republican and Democratic candidates and their super PACs release their latest campaign finance reports. What is known so far is that Bush and Right to Rise spent at least $82 million, both in operating expenditures through the third quarter of 2015 and on ad spending through this month.

The campaign finance reports also show that between June 2015, when Bush formally announced his candidacy, and September, the Bush campaign spent $1.2 million on private planes versus the roughly $700,000 spent during the same period by Democratic front-runner Hillary Clinton.

Cruz spent $158,000 on private planes, and Rubio $293,300. Trump flies around the country in his own Boeing 757.