It’s important to know that you have to read the fine print, as they don’t mean the same thing at every school. What one school calls REA is different than what is REA at a different school. Look at Princeton vs Notre Dame vs Georgetown, for example.
And while “better” does indeed vary according to individual circumstances, typically ED>ED2>EA>RD in terms of acceptance rates. ED/ED2 increases the chances because colleges care about yield (some care A LOT) but the numbers can be deceptive. When you adjust for interest groups the bump in acceptance rate may not be quite as large.