The Flux GU15 looks just like the GM30 but rides exactly the opposite and it’s a really good freestyle binding. The Flux GU15 is a solid choice to go with a soft easy turning rocker park focused board.
Flex: The high back has Urethane blended in to make the high back pretty soft. It still has some response that allows you to make a heel side turn but it’s very tweaky.
Adjustability: All Flux Bindings these days are almost tooless so the only thing you need a tool for is to screw on the discs.
Comfort: These straps are pretty comfortable
Heel-Toe Response: It’s more than you would think for a binding with urethane but it’s still not a really responsive binding. It has a nice smooth response.
Tip-Tail Response: It’s not going to offer much of a more lively flex under foot compared to some bindings and there is a dead spot under your foot. It’s still a very supportive binding so it allows you to flex a board lengthwise better than you would think.
Boot Support: The GU15 does a good job of holding your boot in place and giving you good support without sacrificing comfort. There is a consistent theme with all Flux bindings and that is you don’t have to crank them down as hard to get good support.
Ratchet System: Very good ratchet system. It doesn’t require much work putting on or taking off your straps and they rarely come undone.
Shock Absorption: Our one major complaint is the minimalist padding in the heel of the base plate. Many people like the skate like feel and will disagree with this complaint but we like padding and want to continue to ride when we get old.
Other than the shock absorption issue the GU15 is a well made park binding that will pair up well with any soft board and boot.