Systematically turning down the first girl who approaches you is a knee jerk reaction. You have to distinguish between a Door Vulture and a girl who just happens to be first. Perhaps on your first few trips you won't be able to distinguish and you'll be better to just turn down the first one every time, but that's not a good long term strategy in my opinion.
I'd say be leery of the first girl who approaches you, but don't just automatically turn them down. Read a bunch of reviews, you'll quite often see stories of guys turning down the first girl because they just arrived only to spend the rest of their visit trying to get her attention again. And you'll read a bunch of stories of guys who walked in, talked to that first girl, and walked out happy. There will be some tales of woe as well, but they aren't predominant.
Many, many times I've had a great time with the first girl who approaches. Not Door Vultures mind you, but not every girl who happens to approach early on your visit is a door vulture. Sometimes it's just dumb luck, she happens to be making a lap looking for interested customers & I happen to have just walked in. Many, many times I've had poor experiences with dancers who wait a while to approach.
I have seen correlation between Door Vultures and ROB techniques, but I haven't seen anything to suggest the Cuban's do it more than any other type. In my experience, it's usually dancers who are older or otherwise less universally appealing without regard to ethnicity. As an example, the south Florida clubs are loaded with Clubans. But very few of our clubs have regular Door Vultures. The clubs that do, are the ones that have a wide range in dancer quality. In the clubs where 6's have to compete with 9's, the 6's often resort do Door Vultureing. I also see that technique a lot from traveling dancers, so clubs that hire them often have a couple door vultures.
And for me at least, almost everything in the strip is a sliding scale with respect to hotness. I'm more willing to take a chance on a dancer with a few imperfections in her approach and attitude if she's smoking fucking hot. But a dancer with a middling appearance pouncing on me the second I sit down and immediately pushing for a dance or a room isn't gonna get far.