I am thankful to Samsung for all the three Z series phones I have, Z1, Z2 and the Z3. All three are awesome phones in its category. All the three won them through competitions, participations, etc… Not only for this but all the developer devices, gift vouchers and support I got for developing apps.
The speciality of all these phones are they are the smartest in their category. All the phones have Tizen OS which is developed by Samsung.