I've been successfully using Symlin for over a year now. I followed the directions on the packaging and too from what I read in the online community. To start I reduced my basal and I:C ratio by 50% and then made adjustments from there. I inject 45mcg with each meal, so three times a day I inject; I don't inject for normal snacks. I wear an OmniPod and Dexcom. Remember to NOT inject Symlin with or near your insulin injection; they don't mix and Symlin will harm (crystalize I think) insulin. I have gone as high as 60mcg, but I much preferred how I felt and how my BG reacted with the 45mcg and, like I said, it's been over a year now. I found, like you, my numbers dropped greatly and I was shocked, to say the least, and that was with less insulin. I had some short-lived belly problems. What I found most interesting though was for years I thought I was lactose intolerant, like my Mom. All treatment for that condition came to a halt with the Symlin, which, along with everything else it does, helps slow down digestion.
Edit - take-two: I edited this but it did not hold; here's hoping this one does. You have to increase your dose slowly from 15mcg and have it work for three days without any problems (belly, lows,...) before you increase to 30mcg and have it work for three days, then 45mcg ... and so on until you reach 60mcg or the dose which does the best for you.