Know thyself! Personally, it has no effect in my sleep, although I have rarely smoked right before going to bed. But it is the same with nic-hits: pipe blends which according to some smokers here pack a wallop do not hit me so much, whereas many (even mid-strength) cigars will have me in cold sweats by the half-mark. As Cosmic says, it must be related to blood sugar levels: if I have a couple of sugared drinks along with the stogie, I can enjoy a strong robusto.