Wow I'm surprised you're really getting that much battery life. I was thinking that my more powerful SB (i6/16GB/512), like yours, might just get lower battery life than the claims that were tested on lower-end models.
I'm on my second SB, and on both of them I've got about 6-7 hours at 50% battery, with battery saver on, a few Office programs open and keeping Chrome closed whenever possible because it shoots through battery.
Can I ask what you're usually doing getting this battery life? And does this include short periods of sleep or is this what you would get using it straight through. r
Well, heck, who works with his SB turned on for 8 or 12 hours and doesn't stop to eat, stop for a restroom break, stop for a phone call, stop to talk with someone who stops by, etc. Yes, my SB will be turned on for that period of time. I use "sleep" during the day and absolutely love it when my gorgeous face wakes it up. So, yes, I get that kind of battery life, but I think that I also use my SB much like a normal person might.
I'm a self employed stock market trader and have been for the last 15 years. I only trade my own account. My office is in my home. So during the market day I'm running Interactive Brokers Trader Workstation and I'm looking at a lot of trading sites and doing a lot of chart comparisons and analysis. I'm a very active short term swing trader with some day trading mixed in. I use Microsoft Excel with my Microsoft Office 365 Subscription to do market analysis and keep track of my activities. I used to trade with multiple large screens on a heavy duty tower but find I now prefer to use just the single high res screen on my Surface Book. I feel no need to get the Surface Dock and add any more monitors for the way I like to work today.
I'm also an avid amateur photographer and I do a good bit of work with Adobe Lightroom/Photoshop CC Subscription. LR/PS makes very good use of the GPU and runs Lightroom/Photoshop CC quite noticeably faster than my Surface Pro 3 which is also sitting beside my Surface Book. The Surface Pro 3 is an i5/8GB/256GB. As an aside I did pick up the Surface Pro 4 keyboard with the fingerprint reader. Highly recommended if you have a SP3.
15 years ago I retired from my old day job as a Microsoft Windows programmer to trade full time. So I still do a bit of Windows programming running Microsoft Visual Studio 2015. Visual Studio 2015 makes good use of the GPU and is also quite noticeably faster than my Surface Pro 3.
My Surface Pro 3 sits here running in case I need to go to a backup machine during the trading day, but my Surface Book has proven to be reliable and I've never needed to go to the the SP3 so far.
So there's a picture of what I do during the day with my Surface Book i7/16GB/512GB. I really do love this computer!