Well I guess that's as fast as you can get that 850 to run on your particular notebook. You know what is possible as you seen my AS scores, my boot up time is about the same as yours, about 15 seconds to log in and another 15 or so until I have full mouse control. I have a lot of crap running in the back ground 4 Gadgets, 2 AV AMalware, Adobe CS4 start up is slow but compared to a hard drive its miracle. My 850 is noticeable faster than the Liteon SSD was.
For faster boot ups look into what is load up on boot! eliminate what you really don't need starting up every boot.
G752VY-DH72 Win 10 Pro
512 GB M.2 Samsung 960 Pro
1 TB Samsung 850 pro 2.5 format
980m GTX 4 GB
32GB DDR 4 Standard RAM
Z97 PRO WiFi I7 4790K
Windows 10 Pro
Z97 -A
Windows 10 Pro