Holy smokes! I was trying to find out about the whole Triangle-K hechure issue to learn what the story was. After some searching, I found a website by the Canonist which gave some good commentary and an interview with Rabbi Ralberg regarding the Triangle-K hechure.
As you know, upon getting married, I was still eating Triangle-K totally oblivious to the various arguments. However, my wife was shocked when she found out I was eating it and she forbade me from eating it.
Back in law school, I asked a Rabbi (who is no longer with us) what the problem was -- he told me that it was difficult for the triangle-K hechure to supervise everyone, so just be careful and check the ingredients with the company before eating the food willy nilly.
More recently, in my Lubavich circles, triangle-K is only considered okay for some foods which generally don't need a hechure, but is frowned upon for pretty much everything else. This being said, in our home and when eating out, we keep cholov yisroel, pretty much pas yisroel (there have been some exceptions), and are otherwise very strict in our kashrut. I don't think, however, that one who goes to the convenience store to pick up a bag of potato chips or Sun Chips which are triangle-K (such as what happened a few times when I had an overwhelming desire and there was nothing else available with a more credible hechure) would be breaking halacha. Those few times it would happen to me, I would hesitate about it and would feel bad about it as I was walking with it to the cash register, but I never would think the food was treif, but rather that I was succumbing to a lower standard of kashrut. That being said, I wouldn't bring it into my house, however, just in case what I was eating turned out NOT to be kosher.
Here is my possibly twisted logic:
1) is it kosher? probably.
2) Is it up to my standards of kashrut? probably not.
3) Will I feel bad about buying it? yes.
4) Will I enjoy it when I'm eating it? you bet, but this isn't the reason I decided to eat it.
5) Again, IS IT PROBABLY KOSHER? probably. I see one flavor has the hechure, the other flavors don't, so there's obviously some selection.
Thus, I didn't feel SO BAD when buying it.
On a more general level, my position of it is that I wish that the hechure were okay across the board. Any hechure with unresolved questions is NOT one which I would openly tell people it's okay to eat, and is NOT one that I would use in my home or encourage my family members or friends to eat. The fact that I find little wrong with buying something like a bag of chips with that hechure doesn't mean that it's okay for others to do the same without first checking things out on their own; it would be a judgment call on halacha and a personal choice between you and G-d how careful you choose to be in your kashrut. That being said, *I MUST REPEAT* if I eat it, I would NOT bring it into my house just in case it isn't okay and I certainly would NOT put triangle-K food into anything that I cook, especially when if there is a real kashrus issue with the food, it would destroy the kashrus of our home which my wife and I so carefully guard.
That being said, I encourage Rabbi Ralbag to be more proactive in countering the accusations about his certification. There are a lot of rumors flying around, and he should either admit guilt and change, or aggressively refute the accusations with proof.