Think of it like this; every flipper is going to feel a little bit different. It takes a little bit to get used to it, but once you do, you'll flip it with no problem. I'd spin the question the other way, and ask what makes a really BAD flipper for you? Then we know what to avoid.
If you want to just "flip it and forget it"? You may prefer some of the assisted openers. I can cite the example of the Kershaw Leek; a little more than a nudge on the flipper and it flies open. That has a certain feel.
If you want buttery smooth, you're probably talking about bearings. I have a Boker Urban Trapper (G10 scales) that I carried for a year that I love. It took a couple of days of occasional flipping to get the feel for it, but now that I do, it feels great to deploy. (I find the flipper tab a little sharp for my taste, but that's another thing.)
I've read many great things about the ZT Sinkevich knives; I looked closely at a 0450 at my local knife store. Nothing makes you feel sillier than holding a flipper knife for the first time in a middle of a busy store that you CAN. NOT. MAKE. OPEN. (In hindsight, I was squeezing the lockbar against the blade. User error, I suppose.)
For the best in mall ninja cool feeling, it's hard to beat the $4 Ozark Trail tan G-10 flipper I bought. "Subtle wrist action" is an understatement; the motion was smoothing more like launching a Frisbee, but otherwise the flipper tab would open it about 1/3 of the way. But hey! It was $4, its value exceeded its price, and I happily passed it along to my son.
I find it maddening to try and read between the lines of peoples' experiences to figure out what is a real flaw and what is someone's perception. That tends to magnify issues in my mind larger than they really may be. Think about the aesthetics you want and the feel you're after, and see if that helps narrow the field down.