There are at least 4 racers at our club using these batteries. All of them agree they are very, very good for the money. They (me included) are going to keep using them and not bother with dearer batteries. The only time we have had any issue with them was when I left one in a car plugged in and turned on for about a week. Its now dead.
No swelling, no fires just good service from them and they have been used for stock and mod in both onroad and offroad.
Is your car slow..Xray it!.......FK05, M18, M18t