Ha! Birdstrikes, I have to agree 100% with your sentiments. I am disappointed that pilot pay at the supplementals has been stagnant for so long. But, It is what it is...... Theses companies will fly and their aircraft will be crewed because at the end of the day, guys want to fly more than they want to sit at home or work regular jobs.
A few years back SA hired me as a direct entry capt on the classic. The training was fine and I thought the check airman were pro's and good to work with. I enjoyed flying steam gages again and the line guys were fun to hang with on layovers. After a while I ended up on the 777 doing laps around the world.
I don't recall being called on my days off, paychecks were on time and cashed, and my trips were generally 15 to 16 days total (on the 777). I did quit in 2012, but not because I didn't like the company.
I had a great job for 20 years with a good contract so I do know the difference, but that doesn't mean that these supplemental jobs aren't worth your time.