The battery life is bad. There's no real point in pretending it isn't. That said, I'm not really expecting tablet-level life on something that's essentially a laptop. What's really bad, however, is mine can be asleep and still drain completely in under two days. Meanwhile, my work-issued macbook air I turned on for the first time in over a month, and it still had juice in it. Obviously, even when "sleeping", there are a lot of things still going on under the hood in the Surface. And, I can't really blame Windows, as I've had plenty of Windows laptops that do not have heavy battery drainage while sleeping. It's really weird, and annoying, and I can't remember the last laptop I've used where I felt so tethered to a power supply (probably back in the early-mid 2000s when I was under the spell of the promise of 17" behemoths replacing my desktop while still providing portability-yes, laugh away).
As for the wi-fi issues with the Surface Pro 3...back in October, I was finally able to solve it by just installing the Windows 10 Tech Preview. All the issues where the wi-fi failed when coming out of sleep (fixed by turning wi fi off, then back on) vanished. But, the last firmware update that was supposed to (yet again) fix the wi-fi issues has now broken my wi-fi again, so now even on the Tech Preview I am forced to turn wi-fi off, then back on, every single time I take my Surface out of sleep. Over the course of a day, that is a lot of times, and if I had actually purchased this device and it wasn't something issued to me by my workplace, I'd be metaphorically throwing it through several windows. I've owned a lot of devices over the years, and this wi-fi issue is just absurd. I've literally never seen such a lingering issue play out like this before.
I've made my thoughts clear on the cover keyboard before, but it is worth reiterating. It's not good. It is far too flexible, which results in a horrible touchpad. A youtube video of me at the tail end of a long day trying to click on a super small link while the damn pointer constantly moves due to the touchpad flexibility would probably be hilarious.
The Surface has its moments. I actually sort of like it as a tablet, though there's so little in terms of tablet-like apps that are both available and I would actually use that 99% of my time spent using it as a tablet is in "desktop" mode. In fact, I can't think of a single metro-style app I actually use on it. The hardware/size/form is nice. If there was an android or ios tablet with this body, it'd be pretty fantastic (both platforms in which I do actually spend time on tablet-style apps on my own personal ipad and nexus 7). And, to be honest, I suspect half the time I'm using it as a tablet in desktop mode is just to avoid the horrible trackpad in the cover keyboard.
One last thing. The kickstand is a nice idea, but at the end of the day, it also means when you're using your Pro as a laptop, it is taking up more real estate than an actual laptop.
Outside of the first 5 minutes when I unboxed it, I've never used the pen. I'm not even sure where I put it at this point.
If my work had actually asked me before thinking they were doing me a favor by purchasing me the Pro, I'd have asked for a Windows-based ultrabook instead.