I voted neither of them coz i used both bitdefendor and McAfee...Eventhough Bitdefendor has a very good detection rate its very buggy and makes boot times longer and also support is bad....for Mcafee my lappy came pre installed with Mcafee..its very resouce usng and slowed my lap a lot..Its detection rate is also not very good.
Currently im using Kaspersky Internet Security 2015 for around 6 months..Ive not faced any problems till now...its better in terms of perfomance and protection when compared to McAfee...You can gor for KIS or others such as EsetSS,Emisoft IS,Quihioo TS whch are better in terms of perfomance as well as protection..