Globe & Mail games writer says he prefers the brevity of Gran Turismo 5 Prologue to other racing games that are "ridiculously epic in scale." From the story:
"They have hundreds of cars, the majority of which I have no interest in (I don't need to try driving every kind of Integra ever designed to understand that the vehicle is fundamentally an ugly, wannabe sports car-one will suffice, thank you), and hundreds of racing challenges, which tend to get longer and more repetitive the further you progress.
Prologue, on the other hand, has a relatively modest but still diverse selection of about 70 cars, around 40 races, nearly 20 tracks (counting alternate and reverse routes), and a nice little online racing mode. I wish we were able to modify and upgrade our cars a little more, but other than that I think Prologue is actually a reasonably robust and sensibly long racing experience. I've yet to finish it, but I'm guessing I'll end up spending about 10 hours on the career more, maybe half a dozen hours online. Just the sort of commitment I like to give most games..."