I'm one of the people you refer to that paid nearly 3K for my Surface Book. Knowing what I know right now, I'd definitely buy my Surface Book again as I really love this machine, what it does, and how it does it. The only problem I'm seeing at this point is the video driver that halts and then immediately comes back on again with no loss of data. It happens only occasionally and only when I'm using my Internet browser. For me that is definitely no show stopper. Microsoft stated in these forums that they are actively working on this one.
I've made my living trading the stock market full time for my own account for the past 15 years using Interactive Brokers Windows trading platform. My Surface Book works flawlessly for my trading. If any computer gave me any problems in my trading, I wouldn't be using it.
I'm an avid amateur photographer and I use Adobe Lightroom/Photoshop CC every day. I maintain a personal web site and blog using WordPress. I make extensive use of Microsoft Office 365 and Microsoft OneDrive for data storage. None of these applications give me any problems whatsoever and run flawlessly.