The problem with Glinthawks is that they're either so trivial they don't even qualify as a nuisance (if you're wearing good cold resist armor) or a huge healing item sink (if you aren't). There's no way interesting way to fight them. By contrast a melee fight against ground-based trash mobs was by default an easy win, but always had the chance of going wrong if you slipped up.
Yeah, that was a good fight. Especially since that was the fight that really thought me how useful taking out specific modules is, and how best to do it. That fight at a low level is just a total pain unless you can take out the burrowing modules quickly. The other thing I liked there was how the story around that side quest hinted at the sound sensitivity of the Rockbreakers without outright stating it. So it felt like I was actually being clever and discovering it myself, even though it was actually being spoonfed by the game :)
Not sure I'd call them my favorite opponents though. I only fought them twice, both times during missions, and avoided them in the openworld. By contrast, I made occasional trips to clean out Thunderjaw and Behemoth areas just for fun.