North sells a slightly cheaper but similar device called a Tack Strap. It's made without the hard plastic parts
of the ATN.
I have one that I use with a symmetrical spinnaker
when shorthanded. It works great and is easy to set and douse singlehanded along with the help of a Snuffer. With the symmetrical spinnaker
carried out to leeward you will certainly death-roll when the wind
builds. Much sooner than when using a pole. I don't know if the asym spinnaker has the same characteristics.
There's a short snippet of one in use in the video trailer at: Sailing America - Cruising the San Juan Islands: Friday Harbor, Victoria & Port Townsend
I also have an ATN Topclimber that works very well.