babygro you wouldnt advise starting them in a say 3G or 5G pot from seed then?
I think people do both and get successful results doing both, but in my opinion, if you want the best yield possible, it's best to start out in a smaller pot and let the rootball develop into a nice tight mass of roots, which will give it the best opportunity for filling out the larger pot when you repot it. One of the problems of going strraight into larger containers is that 1) the rootball hasn't yet developed properly, and 2) the taproot tends to simply grow straight down and then out, rather than growing down and out gradually when the rootball has been allowed to properly develop.
A plants roots are vital to the correct uptake of water and nutrients and a wide and well spread/developed root system will allow the plant to grow healthily and vigorously.
People tend to go directly to big pots because they don't like repotting them and I can't blame them - I hate repotting, it's my most hated job, it's a delicate procedure, difficult enough with only one person doing it and very easy to damage the plant, but as I've said to get the best results, in my opinion, the rootball needs to be properly developed initially in smaller pots.