I honestly don't think being a CFI makes you a better F/O. You can learn how to pass a checkride without instructing. I failed my oral the first time, and I was a CFI. However today was my first sim lesson and it quickly became apparent that my experiences as an instructor were going to help there in a few ways. The first few minutes were ugly today. I did what I'd make a student do and get back to basics. Within 5 minutes of this choice it started coming together.

How many regionals hire F/Os? Most are hiring captains. This is where the CFI becomes big. Ok, so flying around in a 172 around the pattern with a student isn't the same. Neither is flying a 172 around during your training. Why not skip the step all together and go straight to the jet? As a CFI your workload can get very high, especially with new students or when you're doing more advanced training. The task management is just as high, especially in a high-performance aircraft or twin and on final you're not moving that much faster in an RJ (20-30kts).

Blastboy, I really liked instructing. I'd go back to it in a heartbeat if I could make a living doing it. Enjoy it, get as much as you can out of it and in return your students will as well.