But reservations have been overwhelmingly tempered by praise for Richard Jones's luridly theatrical production, some splendid ensemble singing and in particular Pappano's masterful conducting of the difficult score.
Pappano is happy to acknowledge that, "when pieces are not famous, there's usually some reason for that". And in this one he concedes, "the lyricism is very parsimonious". "But," he says, "I'm thrilled that everybody's appreciated the tremendous amount of polish and spirit behind the enterprise".
To help the audience grasp the quickfire libretto, the decision was taken to perform the opera in an English translation instead of the original Russian. It didn't make Pappano's job any easier though. "My main preoccupation was getting most of those words across, because if you make a decision like that, on the one hand you're doing the audience a favour. But you could be doing them a disservice if the orchestra's too loud all the time, or if the singers are really not clear."
It must help that a number of singers in The Gambler's large cast are British, a fact of which Pappano is proud. "I work with British singers all the time. I think it's one of the richest banks of opera singers." But he's concerned about what the future holds for local talent. "I don't see enough English singers coming through our young artists programme. I'll be honest about that. I think there's a problem there" - one he traces back to the lack of available college places.
There's another problem with singers that every opera house has to deal with, and affects what works Pappano can programme at the Royal Opera House. That's a lack of suitable singers, especially for the heavier parts in the repertoire. "You can't just say 'I want to do Otello'", rues Pappano. "You have to have a realistic idea of who's going to sing that role." This hasn't always been the case - just look back to the glorious recordings produced in the 1950s. So what's changed in Pappano's lifetime? He has a few ideas. "The natural maturation of the voice now is not what it was. We rehearse probably twice or three times as much as any opera singer rehearsed back then. Our presentation is probably better now. The polished perfection, the tightness, it's better. But there's no question that less emphasis on the theatre and less emphasis on looks had something to do with the longevity of the voices."
I ask him if there's too much pressure on the really good singers, the ones with the potential to take on these big roles. "Of course, he replies. "We all want them, and only the really intelligent ones, the ones who are able to build their careers with patience and with incredible strategic forethought will make it." Bad advice, and particularly, bad technique can compound their problems, he says. "Up until the age of about 35 a singer can go on natural talent and physical strength. At the age of 35 something happens to every voice. And that's the moment when the singer really has to know what he's doing. He has to be able to call upon physical knowledge of the throat and the voice and of voice placement to be able to carry that voice on through the next step of the career. And a lot of them don't really know what they're doing. That's scary." He doesn't mention any names, and I don't ask, but I can't help thinking of the prodigiously talented Rolando Villazón, whose promising career has recently been blighted by vocal troubles.
But Pappano is not one to dwell on obstacles. "Believe me, I would love to be doing Otello every season, but there's no Plácido out there at the moment. Pagliacci's a piece that you don't see that often any more - who can sing Canio? It's worrying, but I get on with it. I do other repertoire."
The silver lining to this grim cloud is that it's made room for the Royal Opera House to mount hugely-acclaimed productions of more left-field works like Shostakovich's Lady Macbeth of the Mtsensk District and Birtwistle's The Minotaur, not to mention bel canto rarities. "If the market was flooded with top flight singers for Aida and Trovatore and things like that, by virtue of their popularity, I think our programming would be less interesting," Pappano points out.
It keeps the Royal Opera House Orchestra on their toes too. "They're interestingly sceptical, but wonderfully receptive to new scores," he says, citing last season's first-ever Covent Garden production of Korngold's Die Tote Stadt as one they were "crazy about". Pappano's plans extend out to 2014, and rarities scheduled for future seasons include Meyerbeer's Robert Le Diable, Berlioz's Les Troyens and a work Pappano is particularly looking forward to conducting, Samson et Dalila by Saint-Saëns.
The Royal Opera House is routinely accused of being financially inaccessible, with tickets normally costing up to £210. But for The Gambler the maximum price has been pegged at £50, an attempt, says Pappano, to draw in "a more theatrically aware crowd", perhaps people intrigued by the work's background or the connection with Dostoevsky, whose novella of the same name provides the opera's story line. The ploy seems to have worked. The whole run was almost sold out even before opening, which as Pappano says is, "good, for a piece that very few people know or have even heard of."
But he's just as ready to defend the higher prices too. "I think coming to Covent Garden will always be seen as a special night out, because the quality of what goes on. It's not cheap to come here, but it's not cheap to go to football matches, nor very nice restaurants for that matter" - a fact that doesn't seem to prevent the Royal Opera's productions from selling out on a regular basis. And he points out that although the £200 seats make the headlines, there are plenty of cheaper tickets too.
His tip? "The key to this place is trying to book ahead, especially for the more popular titles, because the less than fifty quid tickets get gobbled up really quickly".
- Jenny Beeston