The kits have the advantage of being convenient (as you said, everything from one vendor). DIY methods have the advantage of being less expensive. Granted, buying everything from scratch to start the PF tek isn't going to be that much cheaper than one of the kits. But doing the PF tek from scratch can produce a much higher yield than the kits, if done right. Not to mention the fact that most of the required materials for DIY teks are reusable, so one's second grow would require a much smaller investment than their first.

All that being said, I am not opposed to the grow-kits. My first grow was with a grow-kit, and I could not have been happier with the results. Money well spent, IMO. I think the kits could be a good option for people who do not have the time or energy to invest in DIY methods, and don't mind shelling out a little extra dough in the name of convenience.

I do agree that one is likely to learn a lot more from the DIY methods than from a grow-kit.