What does it take away exactly? I play games with it on the lowest setting and it usually feels great.
It doesn't ever feel like a true rumble motor, and I don't appreciate it in the same way. It's very noisy and does more to distract than to engage me.
I think the primary difference is, while the haptic motor in the Steam controller does a great job providing feedback on where your fingers are on the pads (I think of it zeroing in on fingers like currents in a plasma globe), it does not give any feedback about directionality of movement through rumble. With a normal vibration motor, you get a sense of push and pull and shifting weight, and the rumble typically syncs with a game to create a more natural sense of action. If you're playing a racing game, and you hit a barrier on your right side, a vibration motor gives you a sense of that drag. It puts more emphasis on certain areas, and performs different motions for different situations. The Steam controller just shakes. So you don't get that sort of individualized feedback. Where another controller might tell you, "you're balancing during a minor earthquake, while rifle fire whizzes past your headone bullet on your left, two on the right; a grenade," the Steam controller says, "a thing happened." It offers no nuance. It trades the brush strokes of an artist for finger paint on a man with no hands.
But I guess I still haven't answered the question. What does it take away? Nothing in any concrete sense. It provides
some kind of feedback. But it's clumsy. After years of gaming with rumble (who else remembers sliding bricks into the ass end of their trident controllers?), I've developed an expectation of a sense of connection between the motion of a rumble and the action of a game. The Steam controller doesn't have that connection, and every time it shakes it reminds me of the disconnect. Does more to annoy me than to give me an appreciation of its suggestion of action.