I could probably write a book in response to this question and not get you an closer. The short answer is, its a crap shoot. The market is saturated with good trainers right now. It is over saturated with trainers in general. Not a week goes by that I don't see someone new advertising a class. Every Tom, Dick, and Harry is hanging up a shingle. One recent one I saw said he has been a LEO for 8 (?) years, and is a NRA Basic pistol instructor. This tells me he knows which end of the barrel the bullet come out of. Often times it is less than that. What a lot of these people lack is experience. Not experience killing people, but experience teaching. You can bet that the students from my first class would get a much better lesson now than they did then. This is mainly because of more time teaching, but also because of myself being exposed to more ideas.
Another guy who recently posted a class on my state gun board is also an officer of unknown quantity. The difference here is that he has contributed good information to the board for some time now and is pairing up with a well known instructor to teach subject matter that is well within his expertise. Something like this is probably going to be a pretty safe bet.
I guess it really doesn't help to suss out local trainers, but one of the best methods I have found for getting a handle on instructors is to attend things like the Rangemaster Tactical conference or more recently Paul e Palooza. At Rangemaster I discovered guys like John Hearn and Chuck Haggard who I would definitely train with, and some other instructors who while they no doubt know their stuff, I would not pay money to be in their presence simply because I don't like their personalities.
Training doesn't have to be ECQV level to be good. It does have to be solid, and you nee to know your weaknesses and what you want to learn to get the best fit. If the price is right, and they are teaching subject matter you want to learn, and they have some good word of mouth, give it a shot. Just remember that if you happened to be impressed, their word isn't law. I have seen a lot of people, even experienced ones, worship at the alter of the most recent instructor.