London 2012 organisers marked the end of the visit by announcing that construction has officially started on the Olympic Stadium, three months ahead of schedule.
Asked how he would mark London, Oswald told a news conference: "9.75 out of 10, as nobody's perfect''.
He added: "The level of detail in the presentations four years before the Games is unprecedented and we have full confidence that we will have an excellent Games.
"We have seen the shape of the stadium, we have see something coming out of the ground and that is a good indication that the Games are taking shape.
"From what we have seen we are very confident we will have excellent facilities for the Games.''
Oswald did warn London organisers however that the spotlight will shift on to them once Beijing is over. He also said there remained challenges over transport, but that this was not a concern.
He also made it clear that the IOC are not concerned about the controversy over the £9.3billion budget for 2012, only whether the facilities and Games themselves will be ready in time and right for the athletes.
Oswald added: "In a few weeks the mayor will receive the Olympics flag and the focus will be on London. The pressure will move from Beijing to London.
"I have difficulty in finding any area where we have concern but if we had to mention something which will be challenging it is traffic and transport.
"There will be additional people coming in to watch the Games and going from one place to another will be a challenge but we know LOCOG has made plans already and with the quality of people on board we are confident this will be resolved in a satisfactory manner.''
London 2012 chairman Sebastian Coe admitted the timing of the start of construction work on the stadium at the same time as the IOC visit was not a coincidence.
Coe said: "Absolutely not, this had been long in the planning.
"This is another demonstration of why it's important to get the events in place as quickly as possible.''
Oswald added that he had been reassured over the progress of the athletes' village.
Only one firm, Australian constructors Bovis Lend Lease, are bidding to the build the village and the Olympic Delivery Authority (ODA) admit that the
"challenging'' global economic climate has made agreeing a final contract more difficult.
The ODA insist that interim agreements with Lend Lease will allow work on the village to start next month.
Prime Minister Gordon Brown met the 18-strong IOC inspection team at the Olympic Park site today where they watched the first work start.
The first phase of construction will see 4,000 concrete columns inserted into the soil to form the permanent foundations for the stadium structure.
During the autumn and winter the stadium constructors Sir Robert McAlpine Ltd will install the floor slabs, the lower tier structures and the columns to support the pedestrian concourse level.
Early next year, the erection of the steel structures to support the stadium roof will start. The stadium should be completed in 2011, a year before the Games.
At the end of his visit, Brown pledged that London 2012 would be on time and within the £9.3billion budget.
He said: "I think that what people do want to know is that it is on budget and on time.
"We already started building this stadium three months ahead of schedule. It is plain that people such as the Olympic Delivery Authority (in charge of Olympic venue and infrastructure) are determined to come in on budget and on time.''