Eug,
Congratulations on trying to get more value for your $$! We need more folks like you.
An easy way to think of certification is:
Level 1 = certified for teaching beginners
Level 2 = certified for teaching intermediates
Level 3 = certified for teaching all levels
Certification is an indication of a minimal level of teaching ability. I'm only PSIA/AASI level 2 certified, but I teach all levels at Whitetail for both skiing and snowboarding. Certification is an indication that you will receive a quality lesson, but not a guarantee. Lack of certification is not a guarantee of lack of quality either. For most East coast instructors, certification costs way more than they will ever get back in increased pay. This is why there are many good instructors who don't get certified.
With respect to guarantees, most resorts will "take care of you" if you have a complaint about not receiving a quality lesson. I know this happens at Whitetail because I occasionally get called in to do "do over" lessons.
For group lessons, you can certainly ask a line up supervisor if a level 2 or level 3 certified instructor is available (arriving early helps). You won't be guaranteed to get one, but you will at least get the supervisors attention. As a backup supervisor, if I got such a request I would either accomodate it directly or, if not, at least let you know if it was possible later during the day. As a rule of thumb I prefer to use certs for higher level lessons regardless of requests. For private lessons, you should expect to get a cert if you ask for one, but you may need to make arrangements in advance or wait for a cert to become available.
I will confess to occasionally using "follow me" teaching. However, there is an art form involved in choosing the right line to lead, the right pace, the right distance to go before stopping, leading and sneaking peeks back to check on form, etc. To the casual observer on the lift it can be very hard to distinguish between an effective follow me lesson and an ineffective one. But I'm not saying that ineffective lessons don't happen.
At Whitetail, we don't have many lessons that go to Exhibition. For many of the kids that end up over there, the bump run is more of a treat at the end of the lesson then a learning experience per se. For bump specific lessons, finding the right line can make a big improvement all by itself. "Follow me" is often the most effective way to teach which bump line to take. For a lot of skiers "marginally able to follow" in the bumps could be a big step up! Sometimes what may appear to be a lesson on Exhibition may just be one instructor in uniform skiing with a significant other or another instructor out of uniform. Although I have no doubt that you could have witnessed teaching techniques that left room for improvement, as a trainer at Whitetail, I'm baffled about how you could have witnessed "watch me and follow me" "several times" throughout the day on Exhibition. I often go long stretches without taking any lessons to Exhibition. We just don't teach that much over there.
If you want to learn more about finding good instructors and teaching techniques, you might want to visit
epicski.com. At Epic we have a listing of certified instructors who are available at various resorts. You can also read through their posting history to get a feel for how they teach. There have been many discussions about finding a good instructor that will pop up if you use the search feature.
A lot of people like to get instructor recommendations by word of mouth. There are plenty of people here and on epic who can recommend instructors they have taken lessons from. There are several local instructors who visit DC ski. Most of us are here to help any way that we can.