I have almost universally found that the brass-framed revolvers are not made and finished as well as steel-framed guns.
I often find brass-framed guns with incomplete polishing around the trigger guard, particularly where the trigger guard bow joins the plate, I guess you'd call it.
Anyway, most of the time I find that steel-framed guns have their tool marks polished out, or nearly so, on the surface. Brass guns often have no or little polishing of the frame, where the cylinder sits against.
The action on steel guns is usually smoother than brass guns. Smoother being a relative term, since some steel guns can have atrocious trigger pulls and you can almost feel each individual burr as you pull the hammer.
And many brass guns I've encountered are equal or worse than this!
External fit and finish are almost always indicative of what's to be found inside any gun.
If it has unpolished areas outside, you can bet that the interior parts will be rough as well.
Years ago I knew a man who had a joking theory about brass frame revolvers.
He wondered, in jest, if apprentice Italian gunsmiths didn't start on brass-framed revolvers until they became competent, then were transferred over to steel frames when they demonstrated a markedly better skill level.
I used to chuckle at that but I've sometimes wondered if there wasn't truth to it.
Of course, like anything, you can find very finely made brass-framed guns and very lousy steel-framed guns.
But on average, I'd have to say that the brass-framed revolvers I encounter are almost always inferior to their steel-framed counterpart, often lying next to them in the display case.
It is not unusual to find brass and steel-framed Remington and Colt copies side by side at gun shows and stores.
So, see for yourself. Ask to look at both of them. My bet is that you'll also notice that the brass-framed versions are rougher in fit, finish and function.