camping

You don't say what you want the hot water service for but I tried several similar units and gave up.

Here is my take way
They are no use for dish washing water, or coffee / tea, only showers.
They are ok for showers but are fiddly and take a long time to get right with temperatures.
You should have them set up permanently somewhere otherwise it will take longer to set up than have a shower.
The temperature can fluctuate from too hot to too cold in seconds if you turn the flow on and off. You can spend your time adjusting flow rates and temperate, and use much of your water before starting to shower.
You tend to use a lot of water.

Note I am not specifically talking about the Kickass one but they are all the same form the ones I got.

You can get everything right, especially if you have a water supply like a river or tap. But in the end it was more trouble than it was worth for me.

Barry,
I have been using a 240v single electric blanket running off a 300w inverter and auxiliary battery for 15 years.
Blanket on setting 2 while around the campfire and you get into a warm dry bed.

happy camper

Barry
A lot of people use a normal 240 blanket and run it on an inverter to warm the bed. Once warmed do you need it again? Perhaps, use a timer to turn it on and off occasionally if more needed during night.
As Boobook said, these type of water heaters are for showering only and use heaps of water. I have a Coleman and it is the same crazy idea and is extremely hard to regulate, when temp is settled the tank is empty. Only way I found is, to run it with a set amount of water in a large plastic tub and heat that first. Then run unit to have the shower and it will accept the warm water and maybe only additional small amount of heat regulation needed. Of course that is more gas though. Having to turn the flow ON and off at any time means the gas also turns off automatically which stuffs the heat of the water and the heat setting you thought you had set, as the gas will only operate when there is water flow to protect the unit. SO use it to heat the quantity you require and then turn off gas and just use the flow of heated water to shower.

Camping - electric blanket - spare me days!

Regards