We purchased a couple of Surface Pro 3's a couple of years ago to trial for our business - had a pretty reasonable run with them, so when the Pro 4 came out at the end of last year, I purchased another three. Thinner, faster, next generation - they could only be an improvement on the SP3, couldn't they?
Here's a list of regular SP4 behaviour:
Not waking from sleep. Doesn't matter how many times you push the power button - no joy. And no LED indicator on the hardware to tell you whether the machine thinks its on or off. Need to resort to hard reset to get any joy.
Crashing during general use, requiring restart.
But most frustrating - the dock! Trying to get the dock to reliably display two external screens requires the patience of a saint. Frustrating thing is, the dock will work fine for weeks on end, and then just stop working, requiring what seems to be endless hard resets to get the PC and dock working in unison again. And you can fix today, tomorrow on boot up, no luck!
If I had a dollar for everytime my SP4 has said 'your pc has encountered a problem and needs to restart to complete' I could retire.
And it's not as if these are cheap kit - we forked our around $2.5k for each machine.
When they are working well, they are a wonderful piece of kit. But it's just too rare. We won't be buying any more, not until MS sort out the reliability issues.