This is a funny subject, sooo many different opinions. First off, you have the people who throw around the "compatible" word. When there is a failure on a forum you will see someone throw out the "your paint wasn't compatible with the primer" or something like that. Seldom is it really an issue IF the replacement is in the same family as the one you should be using.
I am going to throw names out there randomly, they mean nothing other than to make a point.
For instance, if you were shooting PPG urethane primer for surfacing that you are then going to shoot Dupont paint over it, it's still urethane primer what difference could there be from using the Dupont Urethane primer? It isn't like you are using house paint or something, it's urethane primer for goodness sakes. But then you have someone who swears by that PPG urethane primer it is so much better than the Dupont so they are going to use it. Think about this, if it is SOOO much better, than it IS
"different" in some way right?
But tell me, why not just use all the same products? Why mix and match at all?
If there is one thing I learned as a paint rep, most every company sells a pretty similar product, if you are comparing apples and apples. Sure if you used some PPG value line paint and it didn't cover very well and then you shot some Dupont top the line paint it covers way better so you want to use the Dupont over that PPG primer. Why not just get the top of the line PPG paint? If you are comparing apples and oranges of course they may appear to be miles different, the apples and apples are way closer, if not pretty much the same.
I went around to shops all over the state of California (mostly northern Cal) and saw every brand there is performing perfectly for people.That old "Oh XXXX paint sucks, it's horrible" stuff cracked me up. Oh yeah I would think to my self, XXXX is horrible, that's why there are 50 thousand shops in America using it, your COMPETITOR is using it and he is putting out twice the work you are, oh yeah, it's junk.
No paint rep can walk into a shop and blow them away with some product that is far better than what that shop COULD be using in their paint line. I say could be because often they were using some out dated junk like Dupont lacquer primer painting tractors and you come in and show them epoxy and blow their minds. They could have done the same thing with the Dupont, but the Dupont rep didn't show them the epoxy.
So if most any paint line (apples and apples remember) can give you a good system, why mix and match? If you want cheap, go with the value line if you want top of the line go with the top of the line. If you want super durable go with the "fleet" line that they sell to trucking companies.
Choose apples or oranges and then go with the whole line, why not?