I use a qwikclip with my g26 and g19. Works well for me. I also have started trimming the front clips off of the super tucks that I use with my sr9c and kimber custom.
2 clips are going to be more stable and conceal better. It's really not that much extra time putting on a double clip than a single clip in my opinion. The only way I would go single clip is if it's just a quick trip to and from work and you have to change upon arrival - or similar circumstances. If you are gearing up for the day, that extra second or two won't matter.
Qucikclip is ok for a smaller gun. I have 1 for my G27. Also home combat cut it. Much smaller footprint then the supertuck. Not as stable but very doable. I will be using it for an upcoming trip to a theme park.