Hello, this is a funny coincidence, I just posted a sleep related question earlier
I have tried polyphasic sleep for about 4 months and technically its not hard to do it, but it comes at a price.
English is not my best language, so I will try to explain it like so:
Normal sleeping time during the night:
100% concentration during the day
100% awareness during the day
100% energy during the day
Sleeping in 3 sessions, 2 hours each:
75% concentration when awake
70% awareness when awake
60% energy during the day
Basically, it's fine if you do it for a week or two when you are busy, but making this a lifestyle - not a good idea...