hi A.,
Yes, I switched from Synthroid to Armour Thyroid three months ago and have noticed a favorable difference. I was diagnosed with hypothyroidism five yrs ago (after having my daughter). Synthroid worked for me at first but couple yrs ago I began to develop symptoms again, despite testing 'normal'. The other person who mentioned the difference with the T3 and T4 was also true for me.
Also, since consulting an osteopathic physician - I was able to get a more detailed bloodwork done. Regular physicians consider a much more broad range to be 'normal' while you can still be having uncomfortable symptoms.
Since switching to Armour Thyroid I have lost about 6 pounds and have kept it off and I just feel better overall (no more night sweats or lack of energy). To be honest, I changed my diet at the same time - but I think switching to the Armour Thyroid helped make me feel more motivated.
With either med, you know you have to take first thing in the morning on empty stomach and then not eat or drink anything for 1 hour. It can be a pain but it's worth it. I keep mine beside my bed with a bottled water and wake up early to take it and then go back to sleep.
best of luck !