I use VLC media player to review my videos and the screen capture feature to snag stills of whatever I want. No need to mess with switching modes on the camera. I do occasionally carry a compact digicam -- usually an Olympus Tough Cam -- for handheld stills or videos. Mostly I just use the action video camera on the bike or helmet and snag screencaps as needed.
I rarely keep videos unless something really noteworthy happens -- an eventful group ride, dangerous or obnoxious driver, etc. If nothing interesting happened I just delete 'em without reviewing. Especially nighttime videos since my Ion Speed Pro has poor dynamic range and high ISO noise at night -- it's just good enough to identify the type and color vehicle, but rarely any details in license plates.