After much research I bought the Alpha reel and it is pretty cool. http://www.penguinmagic.com/p/S11555
It is an ingenious improvement to the standard ITR in that if the thread breaks it is very easy to get setup again. Like other ITRs, the IT retracts automatically.
Loops are different from ITRs and ITRs are different from other IT devices like the Tarantula. Each hook up has it's pros and cons. Many tricks are possible with loops and not ITRs and vice versa.
To be honest, I don't use my ITR very much. Perhaps someday I will. I did wear my Alpha every day for weeks. It is a great little device and a lot of fun to play with.