Deciding between VMAT IGRT versus CyberKnife

Hey everyone, I was looking to see what those who had either VMAT IGRT radiation or CyberKnife radiation thought about their treatment and why they chose the option that they did and how they're doing? I basically have the smallest lowest-risk level of prostate cancer they just discovered. PSA of only 2.1. Gleason of 6, regular size prostate, etc. And only 46. I'm most concerned about ED and looking for the option with the least ED (and also maybe the easiest path). I've been recommended for either a 28-day VMAT or a 5-day CyberKnife. Active Surveillance seems to much of a repeated hassle as the third option. Thanks for your help.