After beating my head over all the various suggestions like everyone else (to include taping over pin #20 and #51), mine ended up finally being stable and working by leaving the "allow this computer to turn off this device to save power" under Power Management box checked. I removed the tape from pins #20 and #51, too, and it still worked once I had rechecked the power management box. I had unchecked it, since that's my normal default to do so. Kept default settings in Advanced, but changed to: WMM Enabled, Preferred Band (3. Prefer 5.2GHz band), Roaming Aggressiveness (5. Highest), Througput Booster (Enabled), Transmit Power (5. Highest), Wireless device does not disappear when computer is in sleep, etc. Works perfectly, other than not showing 802.11acc in the drop down menus and in netsh, but device speed shows 866.7Mbps, so that's 11ac speed.
Sony Vaio VGN-Z690
Windows 7 64 bit
Intel 17.1.0.19 driver only (no proset)
I also removed my other bluetooth module in the laptop (ALPS), since the laptop would only allow one BT radio to function. When the ALPS radio module was in the 7620HMW BT radio wasn't working, unless I disabled the ALPS module, so I just removed it rather than keeping both devices. BT has worked perfectly.