I've had horrible luck with cell phone holders lol...the best one I've had though was the Grip and Go thing....worst part about it, it fell a couple times off the windshield and the gooey sticky stuff, if it gets dirty on it, the phone won't stick, so you gotta wash it, and then let it air dry.....then my wife got me a cheapo from Sears discount bin for Christmas lol, it's got an annoying clamp on it that you have to pull apart by hand and wedge your phone in there.....avoid bumpy roads though, or the suction cup will fall off your windshield.....and yea if that suction cup gets any dirt on it, it will no longer stick to the windshield (see above LOL).
my wife had the best luck with a Scosche brand that I got her for her birthday, that has vent clips that slide into the AC vents to mount, and it actually holds her IPhone 6S Plus which is pretty wide....and that one wins hands down, no suction cups to get dirty lol....now I can see the "retraction spring" wearing out over time.....as it's got a spring activated thing that holds the phone in place...