ROs make I think 45/hr... SRO vary depending on the individual, but from what I have heard the base pay is at least the 85-100k+ plus 20k license bonus + performance bonus (up to 20-35% of base salary). I am sure some people on the forum may have more detailed numbers than I do. The key is the ability to move up post license. I have also heard that some unions have a set increase in pay to go out of union to management (if anyone can confirm this that would be great... I was told 30%)
I know of a few SROs that were promoted to EM or Mechanical manager, the best part is they still want them to have the SRO license current, so they have to keep that up but get the nice bonuses. It is a LOT of work, but so is an SRO. The best part is no more rotating shift work.