In general, SLI (Seniority List Instructors) get paid what their seniority can hold. They are guaranteed a certain number of work periods a month at 5 hours per period. They have the opportunity to pick up additional periods and doing "doubles" is very popular. SLI duty is both lucrative and conducive to a more normal schedule/home life. SLIs stay SLI's for a long time because it is a great job (and presumably, they are well suited to teaching.) Improved SLI compensation is rumored to have already been agreed to in negotiations. SLI's also experience appropriate oversight.

The training department has a vigorous observation program that weeds out or improves weaker instructors. I was looking to hire a former SLI as a LCP but received negative feedback concerning this SLI's instruction techniques. I was able to look at seven years of observational grades and student critiques that revealed struggles in the first and second year but continual improvement to the point of perfect grades in his last four years. He had followed a normal arc in becoming a good SLI. You cannot hide weak performance or coast with minimal effort. Too many good instructors are available.

If you are interested in SLI jobs at DAL, they are here for sure. Former sim/instructional experience is a huge leg up. And many have been hired into the sim in their first years. Steve Dickson, former VP Flight Operations, became a 727C SLI as a new hire IIRC.