I have an XS (4 yrs old) in my dragster--Great battery so far--no special charger needed as all new chargers have AGM setting
But...
By far and away the best batteries I have ever owned are Interstate
I have a deep cycle Interstate I use in my camping trailer and swap it back to the race trailer to run the winch and it is almost 8 years old still as good as new
XS is a china made thing but has been great for starting a 14:1 engine in a very small compact package for reasonable price
I will never ever use anything but Interstates best unit in my personal vehicles