During our four week stay outside of NY, my wife and I made sure to pick up food in Crown Heights each time we drove into the city. My friend asked me what was wrong with the food where we were, and why I didn't just buy the kosher meat over there.
Here was my answer:
There are other kinds of meats available, but the issue is hechure. There is a stam kosher hechure where many people wouldn't eat that kind of meat because of the chumras in shechita (type of knife used, who the shochet is, etc. -- it's not only what kind of animal is being slaughtered, but it is also the shechita that makes something kosher or not (or today, questionably) kosher).I know by posting this letter I will not only reveal to my friend my identity (because I'm pretty sure she is a reader of this blog), but I might stir some controversy. People might ask, "why cause a separation within the Jewish people? shouldn't we all just be unified as one people?" My answer is yes, we should, but the difficult part of being unified in Judaism is that there are some groups that don't believe in Jewish law and still assert that their food is still kosher, and there are other groups that go to the other extreme and won't eat food which has a lesser degree of kashrut. Hence, it will be almost impossible for everyone to eat the same food unless the higher standards become the norm, because I don't think asking a Jew to lessen his level of kashrut is a realistic, moral, or a workable solution. Hence, we judge each piece of food by its hechure.
Also, some won't readily eat meat from shochets from various sects (think Meal Mart, or remember the Lubavich beatings by the Satmars a few years back, and how as a result the Rebbes said not to eat the other's meat), and vice versa.
Others will eat any meat, even Hebrew National.
If you're Lubavich, there are certain things that you are expected to hold by (e.g. cholov yisroel, etc); having an increased hechure with meat is one of them (e.g. there are two types of hechures on Empire Chicken; those with one kind (I think it's just stam OU), and Empire Chickens with KAJ -- we'll eat the meat with the KAJ hechure, but not with just the other.
I think that's the jist of it -- Lubavichers generally eat meat with chassidishe hechures. That's why it's sometimes difficult when we go out to (e.g.) Doughies. Some of the dishes on the menu are used with one kind of meat, and others are made with other hechured meat. After asking around a few times, I learned to know which hechures were which.
And just think -- there are people that are way more strict on this than I am, and only eat meat not from certain hechures like I do, but only from shocheits they trust.