None.
This car is being used as a taxi. I think this speaks volumes for the build quality of Skoda. I have hired two other Skoda Octavias for this purpose and from a taxi drivers point of view there is no better car on the market.
The fuel economy around town is excellent, averaging 48 mpg.
Reliability is spot on. Absolutely no troubles at all.
Level of trim is generous. (air-con, 6 cd auto-changer, twin airbags, power steering, electric front and rear windows, electric heated mirrors and ABS.
So what, every car brand is used as a taxi somewhere in the world, from a Lada until a Mercedes S class.
What is your point?
The only argument could be that the diesel engine uses less fuel than other brands, but you have to keep in mind that you will need new Turbo bearings every 60.000 to 80.000 miles, so in the end it is as expensive (or even more expensive) to run as any other make.