I've only used jiffy pellets, and i think they work great! and the $$$ is right too!
^ i have to say hes right. but only if you do it right.
i have used rockwool, EZ cloners, jiffy pellets and cloning into cups with soil in them.
jiffy pellets work by far the best for me. i soak the pellets in a dilute (50%) transplanting soloution with IBA(rooting hormone) in it, this way there is rooting hormones inside the pellets. i take larger cuttings and use an IBA root starter (powder) on the bottoms of the cuttings. i keep then inside of a storage tote with a lightbulb inside, and 1/4 inch wholes drilled in the top. perlite on the bottom of the chamber holds moisture, the lightbulb holds the temperature @ 26 C, and with spraying the clones it keeps the chamber @ 90% humidity.
EZ cloner gave me 95% success. and it was EASY, but it cost $200 for the set up PLUS more for the inserts, hormones, and a place to put the cloner..... using the jiffy pellets and totes i spent $45 and i have 100% success.
My answer would be Rapid Rooters.
^ instead of jiffy pellets. inside the tote, with all the hormones. would easily make 100%