read it but just now getting a chance to respond...
Since I STARTED on Armour, I was stabilized on it the best we could, then added the T4 med later. Had I started on something else, I would have wanted to be stabilized on the other first. The reasoning behind this is that changing meds mid-stream usually causes a little back-tracking in your progress.
Another angle on that is that if you are not seeing significant progress with what you are on, one step back so that you can make two steps forward may very well be worth the time, effort, and symptoms.
T3 in and of itself is no miracle as people who have taken Cytomel alone will tell you. Usually, taking a T3-only med leave you low in T4 unless you are taking a T4 med with it. The same thing applies to Armour, but to a lesser degree, since it has T4 in it also, but not enough, compared to the amount of T3 it provides. This is the reason I take Synthroid AND Armour, both.
That is its own can of worms, though, because dose changes involve doing a little math to be able to make wise changes, since I am getting T4 from two sources, adjusting one, means that almost invariably, I have to adjust the other, too.
Adding Cytomel to a T4 med is another story.. doseages are easier to calculate, but Dr. Ridha Arem, Author of "The Thyroid Solution" (a book I HIGHLY recommend) suggests that it is better to stabilize on a T4 med, first, THEN slightly lower the T4 med and add in a little Cytomel. At least that's what he recommends in his book. In practice, I have heard that he has also used Armour as a source of T3 for some people, dosing them similarly to what I am.
A paper written by Dr. John Dommisse explains the importance of using BOTH T3 and T4 in treatment. It might probably be worth your time to find his website (board rules prevent me from linking toit, here) and download the paper or find one of the yahoo groups that has it posted and download it from there. the paper is educational and a good read especially as a supplement to reading Dr. Arem's book.