Thanks for your responses. Further evidence that we're all so different...
I switched to Armour after being on Synthroid. Even with a TSH of 0.4 on Synthroid, I still had all of the typical hypo symptoms. Within 2 months of being on Armour, I felt great, even though my THS was higher.
I've been taking Armour for about a year after taking Synthroid for about three years before then. I just found out that I now have nodules on my thryroid and I have been having terrible episodes of heavy chest pressure, heart palpitations and feeling faint within the past year. I'm going to see my doctor next week and tell him to switch me back to Synthroid, if I have to take anything at all.