I've carried both brands (SIG in P220 & P226) and Glock in 17, 22, 23, 27 and 30SF) over a lot of years and still own both so I don't feel that I'm biased against either one. SIG feels like a glove and is a Cadillac pistol that is basically a 1911 in a DA/SA configuration. Glock was designed for a combat application and is supposed to function flawlessly. I've had FTF, FTE with both although it was rare with both. I wasn't aware of anybody taking a hammer to a loaded pistol but if they do so, they pretty much deserve what happens. I haven't shot a 320 but have read a few articles about the problems with the gun (see links below that include SIG's website).
Like I said above, my recommendation is "I'd hold off" on buying a 320. SIG has a military contract to fill and will obviously figure out the fixes if the proposed voluntary upgrades don't correct the problems. Everybody is entitled to their own opinion and can spend your own money however you like.
https://www.sigsauer.com/press-relea...e-p320-pistol/
https://www.theblaze.com/news/2017/0...wounds-officer
http://soldiersystems.net/2017/08/08...-p320-upgrade/