I’m one of those Charlie/Delta tower controllers in ZBW (and pretty happy about your comment :).
I’d say, yes… controllers are generally geared toward IFR traffic, and for a couple of reasons. One is that the training is set up, understandably so, starting with DEL/GND, then TWR, APP, CTR. There’s a natural desire to move to the next level as soon as you can, so, IMO, there’s not a lot of time spent at a Delta or Charlie perfecting VFR operations. Also, the nature of the top-down environment… if you’re controlling a center position, you have an enormous amount to know about every airport below, and handling a VFR flight out of Delta amidst all the other aircraft is quite a feat, and takes many iterations to nail down.
A few suggestions:
First, file a flight plan even for VFR neg FF flights. Of course it’s not required, but it helps a higher up controller immensely. You can still make your calls to ATC as if you didn’t file it, and If they’re good about it, to maintain realism, they’ll still ask you for all that info, even if they’re just reading along with the flight plan you filed. But not having to key in a flight plan for you does take some stress away, and they can focus more on your particular request and the local airport.
Second, fly the flight again in the same session. Most controllers are learning just as much as the pilots are. So many times I’ve made a mistake and thought, “If I could just have that back so I could get it right”. Well… maybe go back and give the controller the same scenario; maybe they’ll do it better the second or even third time around. That repetition should help things stick, and everyone will be better for it.
And third, if you run into a controller who does a good job, note their name and then keep an eye out for them on their ARTCC’s ATC schedule (if they have one). You can also ask them via chat, or even on frequency (“Denver Center, Cessna 1234, Question when you have a moment”) and ask them when they expect to be on again. I know I’d feel more obligated to put up and stick to a schedule if I knew pilots were out there looking for me.