Ds3,
As I review my 172RG Flight Manual (I don't have one for a regular 172), to assure that I understand what Cessna expects for speeds before I comment (afterall, they are the experts at this). The normal takeoff says to "Lift the nosewheel at 55KIAS". For the short field takeoff the reference to a speed is replaced by "Maintain slightly tail low attitude". It appears that Cessna (at least for this aircraft) is not requiring any particular speed for a short field takeoff.
Differing years of Cessna flight manuals will have differing phraseology for the same technique, mostly from the evolution of flight manual development and harmonizing the procedures with other types as required.
None the less, you will never go wrong using a short field technique on a longer runway, and it's better for the aircraft. You might have to work a bit more at directional control, but nothing wrong with perfecting your skills that way.
If you are flying a multi crew jet, and the pilot not flying is calling out speeds, then certainly "rotating" at a called speed is appropriate, that's the way those planes were designed to be flown. However, I am critical of a 172 pilot who is "eyes in" on, or close to the ground. . You can feel everything you need to about how the plane is flying, and what it will do next, at those lower speeds. Touch is a sense, as valid as any other, so hone it, and use it along with all the others. One day, out of necessity, you will have to maneuver, with reference to the outside, and you just will not be able to look back at the speed, so you might as well practice.
Of more than 60 light aircraft types I have flown, there is exactly one, which no matter how much attention you pay to the feel of the pitch control, cannot be flown in the extremes by feel alone. The control forces are often null, and sometimes backward. I am not surprised that Canada did not type certify it. That is a Siai Marchetti 1019. Magnificent fun to fly, but you cannot relax...
As said earlier, it is not the "new" pilots I blame for not knowing this stuff, it's the inexperienced instructors. The problem is that many of these instructors don't know that they are inexperienced, so they genuinely think that their way is the right way. They were taught to teach by a curriculum, which did not properly address some aspects of flying. So they don't practice, and the center core of knowledge and technique becomes the full breadth, by a narrowing of the range of experience. Yes, there are many things I will do while flying a plane, which I would never write here. I can do it, and I can mentor it to other pilots, but I can not do it justice in words alone, and I don't want someone screwing up because they tried, 'cause I wrote. Yes, I have many times reselected flaps during takeoffs, but only on 180/185 floatplanes, where the trick really does work, if well co-ordinated. But, just the blanket statement to try it, verges on irresponsible, in the absence of one on one mentoring.
At least in the old "hanger talk" days, there was a chance that when the weather cleared, or the following weekend, the wise skygod would say "c'mon, I'll show you" and you were treated to a real experience. The chat group is a fantastic beginning point in mentoring, but it rapidly falls short when it comes to the follow up of "come with me...".
So some of us here do our best to share our knowledge as best can be done by keyboard, and the odd photo. We can only offer so much though, without being in the plane with you....