A lot of it kind of depends on your views personally. Everyone here can say the RJ course is a waste of money and time while others think it is a great way to go. I agree that you should probably instruct for awhile or at least instruct and apply to 135 carriers in the mean time. Just make sure you find an instructing job that DOESN'T have a contract otherwise depending on the market you could get screwed.
As for what I think about the RJ transition course I thought it was a very helpful to take and put me ahead of a lot of people who did not take it or didn't have the option of doing it. I say do it but like others said, don't get the whole shiny jet syndrome in your head. Take from it instead on the operations of the way things are done. Otherwise good luck with what you decide in doing.