The Mist King system is awesome. I have had mine for 3 months and it has changed my life (no more hand cramps from manual Misting). If you only have the one cage to mist the Starter System is $99.99.
One of the reasons you see more Mist Kings for sale (over other systems) is people upgrading from the Starter Kit to the bigger pump (Starter Kit can do 10 Nozzles, Ultimate Value can do 20 Nozzles, and the Advanced can do 70+ Nozzles).
Mist King Benefits:
1) Quiet - As long as you make sure to tie down all the tubes.
2) Easy to set up- The hardest part is setting the timer, which is easier than programming a VCR (or a DVR if you are young and don't know what a VCR is).
3) Quality Construction - The nozzles are made from high grade plastics, the tubes are heavy duty, and the pumps are top of the line.
4) Easy to add more more nozzles for more cages
5) Great Customer Service - Marty is here on the forum always ready to help if there is a problem