The gemara disscusses that anyone who makes their geula (the bracha of g'al yisrael) coincide with shmone esre, they won't get hurt that day. Tosfot explains that this means that they do so early in the morning at vatikin.

One would think that with all the vatikin minyanim that we have in this day and age, we'd have very few people hurt. Yet, this isn't the case.

I forgot who says this, but a lot of times when we think alot hashachar is at one time, its really another. This is because the times of the various zmanim all go according to when the PERSON sees it, NOT when it happens in the sky. With atmospheric changes, if shkia is at 6:10, it could really be 6:09, 6:11, or another time, because we may see it differently, due to various pressures in the atmosphere. Since its so hard to get it exactly right, when we are davening around vatikin time, its not really that time, thus we're liable to getting hurt.

Well immediately after it says that the Gemara quotes R. Zeira who said that he davened vasikin and was hurt. R. Yose ben Elyakim basically told him "R. Zeira, you might not have like what happened to you, but I dispute that you were hurt". What does "einu nizzuk" mean? Even R. Zeira didn't know. He thought he'd gotten hurt that day. Normally you wouldn't tell somene who felt that they'd been hurt that they really weren't. Apparently "einu nizzuk" is independent of what you yourself would define as being hurt.

Also, are issurin shel ahavah considered being hurt? If not, then you could still experience "hurt" without it being hurt.

R. Moshe Shternbuch in Hilchot HaGra u-minhagav 62, cites Rav Beronna on 9b as part of his argument that it's incredibly difficult to synchronize davening vatikin properly - if in the days of the amora'im, how much more so today.
The way I understood the comments is that someone can try to maximize the opinions according to which he is yotzeh tefillah ke-vatikin. However, he is fooling himself if he thinks he is the one who knows exactly how to co-ordinate his tefillah to be able to join ge'ullah with tefillah as did the vatikin.