The older R92s also had the front sight integral with the front barrel band, instead of dovetailed into the barrel. This can be bad, or good, depending on who you talk to. Those who don't like the front sight integral with the barrel band dislike the fact that it's not easily changeable. Those who don't like the dovetailed front sight say that sometimes the dovetail machining can create a pinch point in the barrel which degrades accuracy.
My experience with my older R92 in .44 mag vs. my newer R92s in .357 mag and also .454 Casull is that I would prefer the newer dovetail style. I haven't found any accuracy difference at all, and I would definitely appreciate the ability to change out the stock front sight to a fiber optic. Just personal preference though. You can also change the front sight to a higher or lower sight to accommodate your needs. That's pretty difficult with the sight integral to the barrel band.