Some were disappointed that it was just a question-and-answer session with no demonstration of Snapchat's spectacles, launched in the United States late last year, which come with a built-in camera.
One attendee, however, said it made sense not to push the hardware angle too much at this stage.
Few U.S. firms aside from Apple have made big profits on hardware, and camera and wearable gadget makers have much lower valuations than Snap is seeking.
Most of the questions related to how the company plans to manage its engagement with advertisers and users, and monetize that better, according to people who were in the room.
Its responses won over some potential investors.
"Management did a good show, they were very convincing," said one attendee.
Los Angeles-based Snap also plans roadshows in New York, Boston and San Francisco. It expects to price its IPO after the U.S. market closes on March 1, according to a confidential document seen by Reuters.
Some fund managers have said they will stay away from Snap given its decision to adopt a three class share structure — the first of its kind — that will mean shareholders who buy in through the IPO will not have any voting rights.
Instead Spiegel and his co-founder Bobby Murphy will have the right to 10 votes for every share, and existing investors one vote for each of their shares.
"My view would be investors should tread with caution here, the fact the shares will carry no voting rights would be a major concern for me from a governance perspective," Richard Saldanha, global equities fund manager at Aviva Investors, said ahead of the roadshow. Aviva manages 318 billion pounds across a range of asset classes.
Mike Fox, head of sustainable investments at Royal London Asset Management, said the inability to vote against a company at its annual general meeting was a "major red flag" and he would not be taking part in the IPO.
"It is worth noting that while many U.S. tech firms have delivered tremendous returns for investors following their listing, performance of firms in this sector has not always matched investor expectations following an IPO," he said, also before the meeting.
Others were less worried, though.
"Snapchat offers a cocktail of hype, insane valuations, dubious fundamentals and weak governance. However, the same was said about companies like Google and Facebook when they listed," said Geir Lode, head of global equities at Hermes Investment Management.
"For tech companies early in their lifecycle the weak governance structure is fairly typical, and even with those concerns subsequent shareholder returns have often been stellar."
With tech-savvy millennial users of Snap's products able and willing to quickly jump ship to the next Big Thing, there were also concerns about its competitive position versus industry rivals such as Facebook.
"Barriers for entry would appear low here as well, and you could see their demographic — 18-34 year olds — easily shift to another service," Aviva Investors' Saldanha said.