[anonhacker]

It's reasonable to assume I'm hurting my productivity but like I said I'm doing the whole nights and weekends thing, a couple extra hours of less productive work is better than none.

As far as grogginess/tiredness after you wake up goes that's related to where in your sleep cycle you wake up. I use one of the numerous iPhone/Android apps that use the accelerator to detect and wake you up at the end of a sleep phase.