Frank — Thank you for this information. It does assist me; however, it also shows how frustrating the switch from from a MBPR and iPad to a SP3 can be. That list of alterations (I would argue many are concessions or limitations) you posted are contrary to using my two Apple devices. Never have I had to limit them in anyway to stretch out the battery throughout a day. I never go below 50% brightness (most of the time I hover around 75%), let alone down to 25% as you first suggested.
As for comparison of the SP3 to the iPad based on wattage, again, I was making the argument you made of the SP3 vs. MBPs. The specs of the two are irrelevant based upon the MS argument that SP3 can replace both Apple devices. There is no 15-inch SP3 so why are you comparing it to a MBP of that size?
I would think most SP3 advocates would welcome questions from current Apple users as myself. Referring to us as "fanboys" in other posts is discourteous and unproductive.