Results of my "30 day Biphasic Trial" (the " " are because i didnt really finish the 30 days trial):
For the first 10 days i was making it alright. Would sleep for 4.5 hours core sleep (mostly from 00:30am to 5am) nap at various different times in the afternoon.. sometimes i would nap ar 1pm and other times i'd nap at 5pm....
Then after around the 10th day i started developing the BAD BAD habit of once waking up after my core sleep, deciding to take
just a little nap of some minutes more. It ruined the entire biphasic schedule. At the beggining, once i woke up from core sleep, it was kinda difficult to fall asleep again so i was just laying in bed because it was so cold outside (its winter here where i live). Eventually i would fall asleep, and wake up only some 4 hours later (instead of just some minutes)
After a few days, i was back to my old sleeping schedule; going to sleep at 2-4am and waking up at mid day. Even though i tried going back to the schedule, i would unconsciously turn the alarm off and go back to sleep.
Conclusion: Getting used to biphasic sleep schedule is very hard and takes a lot of discipline, and it's gotta be constant, meaning that even after i'm at a month or more of biphasic sleep, even one week of a different sleeping schedule can screw it all up (at least in my case). It takes a LOT of discipline, even two or three days of oversleeping put all the schedule to risk. So lazy people won't get much far on biphasic sleeping (probably thats why i didnt succeed in the long term

)
Right now i'm trying to go back to biphasic sleeping because indeed sleeping just 6 hours a day is much better than sleeping for 8-10 hours a day; much more time available. I'm on the 3rd day of it.
In the first day it was easy waking up, i didn't take a nap so i would sleep more easily for the second day, in which i also woke up easily after the 4.5 hours of core sleep. In the second day i didnt take a 90 minute nap, but rather a 20 minute nap (damn noises all around the house, i feel like killing some people

). Now its 00:50am and soon i'll go to sleep as soon as i feel really tired. Hope i manage to wake up after 4.5 hours of sleep only.