I have run the 925 for years in both my altered and dragster--they work great--only problem we would occasionally shake one to death (it sat between the rear wheels on the dragster. Had no problems in the altered(sat in the nose). The 925 weighs 26 lbs. .
I think the larger sized batteries are not as prone to failure. But with the larger sizes you then get into competeing with Deka, which dollar-dollar is a better battery. The PC1500 does have more power, but it is only slightly and at the cost of a huge price increase.