I don't want to give anyone the wrong impression with my sale; Ron has made a great product, and I can fit in the NetTent without touching the ends. When pitched with at least 6" the Gatewood is far enough from my head and feet that I feel comfortable. For me I just feel a bit cramped when sitting up, as there is no room to do much but stay in one place. But that's not a criticism of the tent, just of my camping preferences.
Todd, to answer your question more specifically, I like to drape my arms to my sides when I sleep on my back, and when I do that, I definitely bump my arms up against the netting. So if this is how you sleep, then it may be a bit tight for you. You definitely do give up some interior space by using the NetTent in the Gatewood, but that's the price you pay for using a poncho (i.e. the Lunar Solo would feel roomier but at the cost of 3-5oz plus carrying a rain jacket).