Something else to consider, if the average person produces between 5-7mg of endogenous testosterone per day then over the course of a week a healthy person would have used somewhere in the neighborhood of 35-50mg of testosterone. This would be used to maintain a healthy balance of testosterone, dht and estrogen.
A 100mg injection gives you about 50mg of exogenous testosterone to play with in the first week and 25mg in the second week. If you are on biweekly injections you can start to feel hypogonadal again. If you are on weekly then the second week your body has about 75mg to play with and you start getting pushed into the "optimized" ranges. Now if you are a high converter to estrogens or dht you may need a little more to reach a good balance and/or arimidex to block some estrogen conversion, but proper use of arimidex should also let you inject less than you otherwise would to reach a good testosterone to estrogen ratio.
You can also see from this example how anything over 100mg weekly injected runs the risk of having excess exogenous testosterone in your body. I would assume if you got very lean and built up some muscle you could minimize the negative impact, but I would want to work up to that and not be swamped with excess testosterone before I need it.
I hope this makes sense. Its off the top of my head so if I have this wrong please correct me.