I'm about halfway through my SSI instructor training. I knew going in that I would have to affiliate with at least one LDS. I considered PADI because there is no affiliation requirement but eventually settled on SSI.
As you can imagine, for me, this thread has been very interesting to read, especially the comments that no "good" instructor would ever have to affiliate with an LDS.
Like many of us here, I have various certifications from various agencies having been taught by various instructors. Some instructors were better than others; in my case, all were certainly competent. I enjoyed working with some more than others and one or two have become friends (even the one I "killed" in basic cave).
I will say, affiliated or not, all my instructors have made suggestions about purchases of equipment, primarily because I asked them their opinion. Were they under pressure from the LDS to push some particular piece of gear? I have no idea, I do know that in most cases I was very happy with the eventual purchase. The simple fact is, most students are going to ask their instructor for advice on gear purchases. Will the LDS benefit, sure; but in my opinion, that is a good thing. If an LDS is really lousy, it is not going to last.
I've assisted in classes as a DiveCon and will eventually take on students of my own through the LDS I work with. In one or two cases, I have not agreed with policies of the LDS and said so. In every case that has sparked a discussion and examination of that policy. If anything, the other instructors and staff try to slow down training to ensure the highest level of qualification among the students. I have also seen on several occasions LDS staff try to talk someone out of buying some piece of gear because it was just the wrong thing, even knowing that would mean the loss of a sale.
As has been said so many times before on this board, it is not the shop, agency or any other factor that makes for good divers, it is the instructor. There are excellent instructors affiliated with dive shops and there are excellent instructors who are independent. There are also lousy instructors in both cases, the primary difference is the lousy instructors who are affiliated with an LDS have someone watching over them; that is not the case with the lousy independents.
Jeff