Mine went back today. i5/256, Type Cover and Complete warranty.
They gave me a small postcard piece of paper with a survey asking why I'm returning it. I gave three reasons. First, I felt that it was a little top heavy. I've had it fall over when typing in my bed, it just seems unstable in some situations. Second, didn't enjoy the typing experience. When propped up the keyboard had too much bounce and was very noisy/clackety. Third, I wanted a system with High Profile settings. The cpu throttling is probably necessary to prevent overheating and to extend battery, I get it But I'm convinced my SP2 performed better because I was able to max out the settings.
I'm eager to see what ultrabook manufacturers come out with for Broadwell. My primary device is a 2nd gen X1 Carbon (i7/8/256) and it's a great performer but the battery life isn't anything to brag about. Broadwell should help with battery and graphics, both are important to me. After a few months with this Lenovo keyboard, though, I don't think I can ever consider a Surface again. Lenovo's typing experience is just that much better.
Things I hope Surface Pro 4 will have:
1. A keyboard that can compete with proper laptops. I'll accept extra weight for usability. Maybe something like the Lenovo Helix (great idea, poor execution)
2. Fingerprint reader. I never considered this until I get the X1 Carbon. Great way of managing passwords.
3. Better temperature management. Fanless? Don't know, but the SP3 got too darn hot.
4. Extra USB port. I use a Logitech MX Anywhere mouse that has a dongle. I refuse to use Bluetooth. Please add a second port.
5. Return of the Power Profiles. I'd rather have that than Connected Standby features.
May all your children be born naked.