I really think it just depends on the type of cinnamon and the dosage listed on the bottle. I'm the one who brought up the blood thinning effects, and I got that directly from a PCOS support website. The poster wrote this about cinnamon usage:
I Want To Try Cinnamon. What Do I Get, And How Do I Take It?
The Cinnamon you get is powdered Cinnamon bark, like what you buy at the grocery store. The variety is called Caissia Cinnamon. Some people prefer capsules, as it is easier to measure and you don't have to have Cinnamon with everything. If you do get capsules, be sure that it is the powdered bark, or at the very least, a water-soluble product. You want to be careful NOT to use Cinnamon Oil, as it is difficult to process and flush from your body, and it does not have the insulin-sensitizing effect. If you are using regular Cinnamon from the store, a teaspoon is about equivalent to 500 mg. You can take it sprinkled on cereal, in tea, on desserts, mixed in applesauce, and so on. While previously, dosages were recommended up to 4,500 mg/day, due to the discovery of Cumarin (a powerful blood thinner) in Cassia Cinnamon, we no longer recommend this. Now, dosages of 500 - 1,000 mg/day are recommended. It may take a little longer to be effective, but some studies show that a lesser dosage can be just as effective long-term. This also reduces the need to gradually work up to your dosage.
Cinnamon can bring your blood sugar down when first getting used to it, so if at any time you get hypoglycemic symptoms (the "shakes", dizziness, headache, nausea/hunger, confusion, the sweats, irritability), treat it with a sweet drink followed by a healthy snack that is high in fibre and protein. You may need to either reduce your dosage for a week, or adjust your eating/exercise routine to better adjust to it.
Remember to take your Cinnamon with an adequate amount of liquid, as you can get "Cinnamon burps". Some women have even burped up a cloud of Cinnamon!!! While funny, it can burn, so it's a good idea to avoid it!
A recent article on the Mayo Clinic website recommends taking it only twice per day:
http://www.mayoclinic.com/health/diabetes/AN00939
But like any other piece of medical news, for every study you find that says "Yes, this helps" you find others that say "Nope, it does nothing".
I personally take one pill before each meal, so usually three per day but sometimes two. I do this because it really does make me feel better if I eat something that is high in carbs (which I try to avoid, but there are times when it's the only option). It definitely makes me feel less tired after a carb-heavy meal. Whether it has changed my blood work at all is an open question since I have not actually had any blood work done and was diagnosed based purely on symptoms rather than blood work since my insurance wouldn't even begin to pay for those blood tests, let alone an endocrinologist.