I am "fresh" to the world of diving, but here is what I have experienced so far. I am PADI certified, OW and AOW, and am in the process of getting my RD cert. I have only been certified since April of this year. The only requirement of my insturctor was that I had my own boots for open heel fins..and I didn’t even have to buy from him. Talon 04 said it, I am an ex-Navy man and it was important that I have my own gear, to me. I asked the instructor about getting my own gear and he showed me what the shop had and then told me to check it out for myself to see if there was other gear, other than what he offered, that I might want. PLUS, I know I will dive alot more if I have my own gear vs. renting it. I know for a FACT that it will get checked for proper function vs. taking someones word for it....just how I roll when my life depends on the equipment. Just for my peace of mind. That being said, I was not pressured at all by the shop to buy "their" gear.
As far as the programs, its been beat in the head with a big stick ALOT about which is better. I cant say, because I am only PADI certified. BUT, I do know that my instructor was very thorough when it came to safety and knowing what to do in case something happened. I have a buddy that is SSI certified and from what we have discussed, the instructor has ALOT to do with what you learn or dont learn.