Here's a personal story. It's about various art schools not CS, but the situation is similar, I believe.
While in high-school, I also studied in art school. The teacher in the art school was a renowned professional, I believe he even had some awards from the ministry of education (we are talking about socialist style education). As part of our activities in the art school we were supposed to learn to talk about what we were drawing. (Artists are also expected to produce statements...) The unfortunate reality of the trade is that the bizarre blabbering of the artist about her work is what makes all the difference, not the quality of the said work.
In an effort to teach us to do this, the teacher required us to start with something like bringing a stool in the middle of the classroom, standing on it and announcing own name and some other personal details, like hobbies etc.
Some kids in the class seemed to enjoy the activity. I wholeheartedly hated it. I thought it was stupid and pointless. I also believed that people should judge artists' work on its own merits, and that using words to describe an art piece is by definition worthless, because would it be possible to use words to describe images, why go to such length as to create those images in the first place?
This practice was novel and quite in contradiction to the education system which emphasized modesty and objectivity, thus seeing such attempts at entrepreneurship as outright evil.
I went to college first in the post-socialist country, then in a country which had no such past, and was basically copying all of its education system from the States. Now commenting on peers' work was a requirement rather than some extravagant way to spend time in the classroom. However, what I also learned was that peer criticism was anything but objective. In fact, social dynamics in a classroom would distort the feedback so much, that it would be much worse than no feedback at all.
Regardless of the quality of their work, prettier girls would get much better feedback than boys with unremarkable appearance. Students who previously received positive feedback from a peer would feel socially obligated to repay the favor. Some people learned to exploit this simple behavior more than others... Not to mention that typically, there were a handful of bright students per classroom, who would either deservedly steal the show from the rest, or would be in opposition, and thus get no (useful) feedback what so ever.
For long time I believed that peer criticism was just a bad practice created by people who never cared to verify how well it actually works / the problems it creates. However, as an adult, I went to school once again, now to study CS. Here, the situation changed: the amount of work a student is supposed to produce and the difficulty of communicating the results of the research is such that it certainly justifies a brief oral introduction. It doesn't feel stupid and the social pressure, while still there, faded into background since it no longer has this strong influence on the reception of your work.
Bottom line
I strongly believe that public presentation is only warranted when the amount of work to be presented is so vast that a synopsis is indeed helpful. Subsequently, I don't believe in immediate feedback, and especially not one produced under peer pressure. Ideally, I'd have a seminar, where students present the results of their research / lab study, followed by an assignment of groups of students to study the results being presented, followed by another seminar where the "study groups" critique the works they were assigned to.