The usual people chiming in about online is rigged, etc.
Here's one REAL difference. You probably aren't going to have as much fold equity in live games as you do online.
Online you make an iso raise to get heads up and it works most of the time. In many live games making the same iso raise will get you two additional callers and you are in a 4-way pot. Making that continuation bet maybe not as effective 5 ways.
Also, if you get raised on the river, the guy is probably not bluffing or balancing his range, unless he's a kid, then maybe.
Also, most people are not aware specifically of how much money is in the pot, at least when it comes to bet sizing. A guy might make what most of the table considers "a huge bet" on the river, but it's only 30% of the pot size. It's more about big chips rather than value of the pot, kind of hard to explain.
Maybe it's different where other folks play......