I don't want to scare you, but I read of people bricking their phone by installing an OTA witb super CID (not with the M8, possibly it was the One or the One X). Yes, even with S-ON, and it was never understood why tjis happened.
So it sounds safer to first set back your CID.
Current phone: HTC One (M8)
HTC HD2 (Dec 2010 - Apr 2014; thank you Leo!)
HTC Touch HD (Dec 2008 - Dec 2010)
HTC Touch Cruise (May 2008 - Sep 2008 [stolen])
Previously: Nokia 6630, Nokia 3510