Nexus 5 or Nexus 6P?

Hello, I have recently started with ethical hacking course and have come to the android hacking part. For this I require a device to install Nethunter. I found out that Nexus devices are best for Nethunter, then comes OnePlus. But I have realised that only Nexus 5 and Nexus 6P support both monitor mode and packet injection on their internal wifi chips. So, I am ready to buy one of those phones but I am not able to decide. Nexus 6P has better battery life, camera, storage, and rest things. But I have heard that Nexus 5 is better than Nexus 6P in monitor mode and packet injection. Could you please comment which of the phone has better and more stable injection support on the internal wifi chip? And which phone should I buy?